diff --git a/src/libslic3r/Arrange.cpp b/src/libslic3r/Arrange.cpp
index 2f4913f378..520f02f5f2 100644
--- a/src/libslic3r/Arrange.cpp
+++ b/src/libslic3r/Arrange.cpp
@@ -29,7 +29,6 @@
 #include <libnest2d/utils/rotcalipers.hpp>
 
 #include <numeric>
-#include <ClipperUtils.hpp>
 
 #include <boost/geometry/index/rtree.hpp>
 #include <utility>
diff --git a/src/libslic3r/Format/OBJ.cpp b/src/libslic3r/Format/OBJ.cpp
index a148fca1f9..6be8e76765 100644
--- a/src/libslic3r/Format/OBJ.cpp
+++ b/src/libslic3r/Format/OBJ.cpp
@@ -1,4 +1,3 @@
-#include "../libslic3r.h"
 #include "../Model.hpp"
 #include "../TriangleMesh.hpp"
 #include "../TexturePainting.hpp"
diff --git a/src/libslic3r/Format/STEP.cpp b/src/libslic3r/Format/STEP.cpp
index 71eb846b6a..e75d1e3d26 100644
--- a/src/libslic3r/Format/STEP.cpp
+++ b/src/libslic3r/Format/STEP.cpp
@@ -1,4 +1,3 @@
-#include "../libslic3r.h"
 #include "../Model.hpp"
 #include "../TriangleMesh.hpp"
 #include "libslic3r/Exception.hpp"
diff --git a/src/libslic3r/Format/STL.cpp b/src/libslic3r/Format/STL.cpp
index 001a3f39e3..eabe867cbb 100644
--- a/src/libslic3r/Format/STL.cpp
+++ b/src/libslic3r/Format/STL.cpp
@@ -1,4 +1,3 @@
-#include "../libslic3r.h"
 #include "../Model.hpp"
 #include "../TriangleMesh.hpp"
 
diff --git a/src/libslic3r/Format/bbs_3mf.cpp b/src/libslic3r/Format/bbs_3mf.cpp
index 990f91ecdf..a429e46720 100644
--- a/src/libslic3r/Format/bbs_3mf.cpp
+++ b/src/libslic3r/Format/bbs_3mf.cpp
@@ -9,7 +9,6 @@
 #include "../Geometry.hpp"
 #include "../GCode/ThumbnailData.hpp"
 #include "../Semver.hpp"
-#include "../Time.hpp"
 
 #include "../I18N.hpp"
 #include "libslic3r/Point.hpp"
diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index f730ea8cac..1b15bad335 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -120,7 +120,6 @@
 
 #include <Shiny/Shiny.h>
 
-#include "miniz_extension.hpp"
 
 using namespace std::literals::string_view_literals;
 
diff --git a/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp b/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp
index 4af27b2ec9..dcf382ad2f 100644
--- a/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp
+++ b/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp
@@ -6,7 +6,6 @@
 #include "../ExPolygon.hpp"
 #include "../Geometry.hpp"
 #include "../ClipperUtils.hpp"
-#include "../SVG.hpp"
 #include "libslic3r/Line.hpp"
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Point.hpp"
diff --git a/src/libslic3r/GCodeWriter.cpp b/src/libslic3r/GCodeWriter.cpp
index a862ebf2f1..72c1812da5 100644
--- a/src/libslic3r/GCodeWriter.cpp
+++ b/src/libslic3r/GCodeWriter.cpp
@@ -1,6 +1,5 @@
 #include "GCodeWriter.hpp"
 #include "Config.hpp"
-#include "CustomGCode.hpp"
 #include "Extruder.hpp"
 #include "I18N.hpp"
 #include "Point.hpp"
diff --git a/src/libslic3r/Geometry.cpp b/src/libslic3r/Geometry.cpp
index 6c097428f4..ca134eda79 100644
--- a/src/libslic3r/Geometry.cpp
+++ b/src/libslic3r/Geometry.cpp
@@ -3,11 +3,8 @@
 #include "MultiPoint.hpp"
 #include "BoundingBox.hpp"
 #include "libslic3r.h"
-#include "Exception.hpp"
 #include "Geometry.hpp"
 #include "ClipperUtils.hpp"
-#include "ExPolygon.hpp"
-#include "Line.hpp"
 #include <Eigen/Core>
 #include <Eigen/Geometry>
 #include <Eigen/SVD>
@@ -32,6 +29,8 @@
 #include <boost/algorithm/string/split.hpp>
 #include <boost/log/trivial.hpp>
 
+namespace boost::polygon { template <typename T> class point_data; }
+
 #if defined(_MSC_VER) && defined(__clang__)
 #define BOOST_NO_CXX17_HDR_STRING_VIEW
 #endif
diff --git a/src/libslic3r/Geometry/Voronoi.hpp b/src/libslic3r/Geometry/Voronoi.hpp
index 23a50bb8f7..c2cd579218 100644
--- a/src/libslic3r/Geometry/Voronoi.hpp
+++ b/src/libslic3r/Geometry/Voronoi.hpp
@@ -6,8 +6,6 @@
 #include <iterator>
 #include <vector>
 
-#include "../Line.hpp"
-#include "../Polyline.hpp"
 #include "libslic3r/Point.hpp"
 #include "libslic3r/libslic3r.h"
 
diff --git a/src/libslic3r/Orient.cpp b/src/libslic3r/Orient.cpp
index d4c840d224..4af8ffe6cf 100644
--- a/src/libslic3r/Orient.cpp
+++ b/src/libslic3r/Orient.cpp
@@ -15,7 +15,6 @@
 #include "Model.hpp"
 #include "PrintConfig.hpp"
 #include <numeric>
-#include <ClipperUtils.hpp>
 #include <boost/geometry/index/rtree.hpp>
 #include <boost/log/trivial.hpp>
 #include <string>
diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index 321fab6310..b47a0f4695 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -83,7 +83,6 @@
 #include "InstanceLock.hpp"
 
 #include <sstream>
-#include "Time.hpp"
 #include "PlaceholderParser.hpp"
 #include "libslic3r/GCode/Thumbnails.hpp"
 
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index de4584829a..4e6ec96ee9 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -98,7 +98,6 @@
 #include "nlohmann/json.hpp"
 
 #include "GCode/ConflictChecker.hpp"
-#include "ParameterUtils.hpp"
 
 #include <codecvt>
 #include "Format/STEP.hpp"
diff --git a/src/libslic3r/Thread.cpp b/src/libslic3r/Thread.cpp
index 066656c9ed..ce3e5e8bdd 100644
--- a/src/libslic3r/Thread.cpp
+++ b/src/libslic3r/Thread.cpp
@@ -22,7 +22,6 @@
 #include <tbb/task_arena.h>
 
 #include "Thread.hpp"
-#include "Utils.hpp"
 
 namespace Slic3r {
 
diff --git a/src/libslic3r/libslic3r.h b/src/libslic3r/libslic3r.h
index bc32a8c60f..d3b0faa57f 100644
--- a/src/libslic3r/libslic3r.h
+++ b/src/libslic3r/libslic3r.h
@@ -38,7 +38,6 @@
 #include <boost/container/deque.hpp>
 #endif // _WIN32
 
-#include "Technologies.hpp"
 #include "Semver.hpp"
 
 #if 0
diff --git a/src/libslic3r/pchheader.hpp b/src/libslic3r/pchheader.hpp
index 401e9b1145..39949b9e0d 100644
--- a/src/libslic3r/pchheader.hpp
+++ b/src/libslic3r/pchheader.hpp
@@ -110,19 +110,7 @@
 #include <cereal/access.hpp>
 #include <cereal/types/base_class.hpp>
 
-#include "BoundingBox.hpp"
-#include "ClipperUtils.hpp"
-#include "Config.hpp"
-#include "enum_bitmask.hpp"
-#include "format.hpp"
-#include "I18N.hpp"
-#include "MultiPoint.hpp"
-#include "Point.hpp"
-#include "Polygon.hpp"
-#include "Polyline.hpp"
-#include "SVG.hpp"
 
-#include "libslic3r.h"
 #include "libslic3r_version.h"
 
 #include <Shiny/Shiny.h>
diff --git a/src/libslic3r/utils.cpp b/src/libslic3r/utils.cpp
index 6205f11219..a8e47ddded 100644
--- a/src/libslic3r/utils.cpp
+++ b/src/libslic3r/utils.cpp
@@ -54,7 +54,6 @@
 #include "Semver.hpp"
 #include "format.hpp"
 #include "Platform.hpp"
-#include "Time.hpp"
 #include "libslic3r.h"
 // For the vendor-installation helpers: the vendor profile version
 // (get_version_from_json) and the preset cache stamp (VendorCacheFile).
@@ -120,6 +119,8 @@
 // We are using quite an old TBB 2017 U7, which does not support global control API officially.
 // Before we update our build servers, let's use the old API, which is deprecated in up to date TBB.
 #include <tbb/tbb.h>
+
+namespace boost::posix_time { class ptime; }
 #if ! defined(TBB_VERSION_MAJOR)
     #include <tbb/version.h>
 #endif
diff --git a/src/slic3r/GUI/2DBed.cpp b/src/slic3r/GUI/2DBed.cpp
index 4bf71c2d50..27199edf5a 100644
--- a/src/slic3r/GUI/2DBed.cpp
+++ b/src/slic3r/GUI/2DBed.cpp
@@ -15,7 +15,6 @@
 #include "libslic3r/Color.hpp"
 #include <string>
 #include <cstddef>
-#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
 #include "slic3r/GUI/Widgets/StateColor.hpp"
 #include <wx/dcbuffer.h>
 #include <wx/event.h>
@@ -29,6 +28,8 @@
 #include "libslic3r/Geometry.hpp"
 #include "libslic3r/ClipperUtils.hpp"
 
+class wxWindow;
+
 namespace Slic3r {
 namespace GUI {
 
diff --git a/src/slic3r/GUI/AmsMappingPopup.cpp b/src/slic3r/GUI/AmsMappingPopup.cpp
index 9f0a26961e..ad657f35b3 100644
--- a/src/slic3r/GUI/AmsMappingPopup.cpp
+++ b/src/slic3r/GUI/AmsMappingPopup.cpp
@@ -2,14 +2,12 @@
 #include "I18N.hpp"
 
 #include "libslic3r/Utils.hpp"
-#include "libslic3r/Thread.hpp"
 #include "slic3r/Utils/WxFontUtils.hpp"
 #include "GUI.hpp"
 #include "GUI_App.hpp"
 #include "DeviceCore/DevConfigUtil.h"
 #include "GUI_Preview.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
 #include "Widgets/ProgressDialog.hpp"
 #include <wx/event.h>
 #include <wx/colour.h>
@@ -57,7 +55,6 @@
 #include <wx/toplevel.h>
 #include <wx/wrapsizer.h>
 #include "Plater.hpp"
-#include "BitmapCache.hpp"
 #include "BindDialog.hpp"
 #include "FilamentBitmapUtils.hpp"
 
diff --git a/src/slic3r/GUI/AmsMappingPopupUpdate.cpp b/src/slic3r/GUI/AmsMappingPopupUpdate.cpp
index 9425b5919d..309cdab868 100644
--- a/src/slic3r/GUI/AmsMappingPopupUpdate.cpp
+++ b/src/slic3r/GUI/AmsMappingPopupUpdate.cpp
@@ -16,10 +16,6 @@
 #include "GUI_App.hpp"
 #include "GUI_Preview.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
-#include "Widgets/ProgressDialog.hpp"
-#include "Widgets/RoundedRectangle.hpp"
-#include "Widgets/StaticBox.hpp"
 
 #include <list>
 #include <vector>
@@ -41,7 +37,6 @@
 #include <optional>
 #include <wx/wx.h>
 #include "Plater.hpp"
-#include "BitmapCache.hpp"
 
 #include "DeviceCore/DevFilaSystem.h"
 #include "DeviceCore/DevFilaSwitch.h"
diff --git a/src/slic3r/GUI/Auxiliary.cpp b/src/slic3r/GUI/Auxiliary.cpp
index 4f4fe8afd3..cabda0fc84 100644
--- a/src/slic3r/GUI/Auxiliary.cpp
+++ b/src/slic3r/GUI/Auxiliary.cpp
@@ -26,7 +26,6 @@
 #include "slic3r/GUI/Tabbook.hpp"
 #include <ctime>
 #include <map>
-#include "slic3r/GUI/Printer/PrinterFileSystem.h"
 #include "slic3r/GUI/Widgets/ComboBox.hpp"
 #include <wx/app.h>
 #include <wx/bookctrl.h>
diff --git a/src/slic3r/GUI/BBLTopbar.hpp b/src/slic3r/GUI/BBLTopbar.hpp
index d9cc65cb4d..9171cc2980 100644
--- a/src/slic3r/GUI/BBLTopbar.hpp
+++ b/src/slic3r/GUI/BBLTopbar.hpp
@@ -4,7 +4,6 @@
 #include "wx/aui/auibar.h"
 
 #include "SelectMachine.hpp"
-#include "DeviceManager.hpp"
 
 #include <wx/control.h>
 #include <wx/string.h>
@@ -12,6 +11,13 @@
 #include <wx/event.h>
 #include "slic3r/GUI/DeviceCore/DevDefs.h"
 
+class wxFrame;
+class wxMenuEvent;
+class wxMenuItem;
+class wxMouseCaptureLostEvent;
+class wxMouseEvent;
+class wxWindow;
+
 using namespace Slic3r::GUI;
 
 class CenteredTitle : public wxControl
diff --git a/src/slic3r/GUI/BackgroundSlicingProcess.hpp b/src/slic3r/GUI/BackgroundSlicingProcess.hpp
index b1020cf4c9..2e98436522 100644
--- a/src/slic3r/GUI/BackgroundSlicingProcess.hpp
+++ b/src/slic3r/GUI/BackgroundSlicingProcess.hpp
@@ -5,7 +5,6 @@
 #include <cassert>
 #include <cstddef>
 #include "libslic3r/Config.hpp"
-#include "libslic3r/Polygon.hpp"
 #include <memory>
 #include <functional>
 #include <string>
@@ -23,7 +22,11 @@
 #include "libslic3r/Format/SL1.hpp"
 #include "slic3r/Utils/PrintHost.hpp"
 #include "libslic3r/GCode/GCodeProcessor.hpp"
-#include "PartPlate.hpp"
+
+namespace Slic3r { class Polygon; }
+namespace Slic3r { class Print; }
+namespace Slic3r::GUI { class PartPlate; }
+namespace Slic3r::GUI { class Plater; }
 
 namespace boost { namespace filesystem { class path; } }
 
diff --git a/src/slic3r/GUI/BaseTransparentDPIFrame.cpp b/src/slic3r/GUI/BaseTransparentDPIFrame.cpp
index 81e0fb7baf..14575aa988 100644
--- a/src/slic3r/GUI/BaseTransparentDPIFrame.cpp
+++ b/src/slic3r/GUI/BaseTransparentDPIFrame.cpp
@@ -4,7 +4,6 @@
 #include "slic3r/GUI/Widgets/StateColor.hpp"
 #include "slic3r/GUI/wxExtensions.hpp"
 #include "slic3r/GUI/Widgets/Label.hpp"
-#include "slic3r/GUI/Event.hpp"
 #include <thread>
 #include <wx/dcclient.h>
 #include <wx/event.h>
@@ -13,20 +12,16 @@
 #include <wx/slider.h>
 #include <wx/dcmemory.h>
 #include "GUI_App.hpp"
-#include "Tab.hpp"
-#include "PartPlate.hpp"
-#include "I18N.hpp"
 #include "MainFrame.hpp"
 #include "Widgets/Button.hpp"
-#include "Widgets/TextInput.hpp"
-#include "Notebook.hpp"
 #include <chrono>
 #include <wx/string.h>
 #include <wx/toplevel.h>
 #include <wx/timer.h>
 #include "Widgets/Button.hpp"
-#include "Widgets/CheckBox.hpp"
 #include "CapsuleButton.hpp"
+
+namespace Slic3r::GUI { struct IntEvent; }
 using namespace Slic3r;
 using namespace Slic3r::GUI;
 
diff --git a/src/slic3r/GUI/CalibrationWizardPage.cpp b/src/slic3r/GUI/CalibrationWizardPage.cpp
index 0c4abb8070..7017d52e34 100644
--- a/src/slic3r/GUI/CalibrationWizardPage.cpp
+++ b/src/slic3r/GUI/CalibrationWizardPage.cpp
@@ -19,7 +19,6 @@
 #include <wx/gdicmn.h>
 #include <wx/panel.h>
 #include "slic3r/GUI/PresetComboBoxes.hpp"
-#include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/wxExtensions.hpp"
 #include <wx/anybutton.h>
 #include "slic3r/GUI/Widgets/HyperLink.hpp"
@@ -31,6 +30,8 @@
 #include <memory>
 #include <wx/scrolwin.h>
 
+namespace Slic3r { class DynamicPrintConfig; }
+
 namespace Slic3r { namespace GUI {
 
 wxDEFINE_EVENT(EVT_CALI_ACTION, wxCommandEvent);
diff --git a/src/slic3r/GUI/CameraPopup.cpp b/src/slic3r/GUI/CameraPopup.cpp
index 299aaa85fc..32e64d5e65 100644
--- a/src/slic3r/GUI/CameraPopup.cpp
+++ b/src/slic3r/GUI/CameraPopup.cpp
@@ -3,7 +3,6 @@
 #include "I18N.hpp"
 #include "Widgets/Label.hpp"
 #include "libslic3r/Utils.hpp"
-#include "BitmapCache.hpp"
 #include <wx/object.h>
 #include "slic3r/GUI/Widgets/PopupWindow.hpp"
 #include <wx/event.h>
diff --git a/src/slic3r/GUI/ConfigWizard.cpp b/src/slic3r/GUI/ConfigWizard.cpp
index 2ff1dd0ee3..1cbadfff01 100644
--- a/src/slic3r/GUI/ConfigWizard.cpp
+++ b/src/slic3r/GUI/ConfigWizard.cpp
@@ -64,7 +64,6 @@
 #include <wx/msw/dark_mode.h>
 #endif // _MSW_DARK_MODE
 
-#include "libslic3r/Platform.hpp"
 #include "libslic3r/Utils.hpp"
 #include "libslic3r/Config.hpp"
 #include "libslic3r/libslic3r.h"
diff --git a/src/slic3r/GUI/DailyTips.cpp b/src/slic3r/GUI/DailyTips.cpp
index 8563766f81..bb7a6f74e4 100644
--- a/src/slic3r/GUI/DailyTips.cpp
+++ b/src/slic3r/GUI/DailyTips.cpp
@@ -9,7 +9,6 @@
 #include "slic3r/GUI/ImGuiWrapper.hpp"
 #include <cstdint>
 #include <cstddef>
-#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
 #include <memory>
 #include "slic3r/GUI/HintNotification.hpp"
 #include "slic3r/GUI/GLCanvas3D.hpp"
diff --git a/src/slic3r/GUI/DeviceManager.cpp b/src/slic3r/GUI/DeviceManager.cpp
index 73b30fe868..64c101671c 100644
--- a/src/slic3r/GUI/DeviceManager.cpp
+++ b/src/slic3r/GUI/DeviceManager.cpp
@@ -1,19 +1,14 @@
 #include "PrinterNetworkTypes.hpp"
 #include "json_diff.hpp"
-#include "libslic3r/libslic3r.h"
 #include "DeviceManager.hpp"
 #include "HMS.hpp"
 #include "I18N.hpp"
-#include "libslic3r/Time.hpp"
 #include "libslic3r/Thread.hpp"
 #include "slic3r/Utils/Http.hpp"
 #include "slic3r/Utils/NetworkAgent.hpp"
-#include "slic3r/plugin/PluginManager.hpp"
 #include "slic3r/Utils/NetworkAgentFactory.hpp"
-#include "GuiColor.hpp"
 
 #include "GUI_App.hpp"
-#include "MsgDialog.hpp"
 #include "DeviceErrorDialog.hpp"
 #include "Plater.hpp"
 #include "GUI_App.hpp"
@@ -90,12 +85,10 @@
 
 #include "DeviceCore/DevConfig.h"
 #include "DeviceCore/DevCtrl.h"
-#include "DeviceCore/DevInfo.h"
 #include "DeviceCore/DevPrintOptions.h"
 #include "DeviceCore/DevPrintTaskInfo.h"
 #include "DeviceCore/DevHMS.h"
 
-#include "DeviceCore/DevMapping.h"
 #include "DeviceCore/DevMappingNozzle.h"
 #include "DeviceCore/DevManager.h"
 #include "DeviceCore/DevUtil.h"
@@ -112,6 +105,8 @@
 #include "libslic3r/PresetBundle.hpp"
 #include "slic3r/GUI/Jobs/SendJob.hpp"
 
+class wxWindow;
+
 namespace fs = boost::filesystem;
 
 #define CALI_DEBUG
diff --git a/src/slic3r/GUI/ExtrusionCalibration.cpp b/src/slic3r/GUI/ExtrusionCalibration.cpp
index a2d14fa370..6c68b716ee 100644
--- a/src/slic3r/GUI/ExtrusionCalibration.cpp
+++ b/src/slic3r/GUI/ExtrusionCalibration.cpp
@@ -1,6 +1,5 @@
 #include "ExtrusionCalibration.hpp"
 #include "GUI_App.hpp"
-#include "GUI.hpp"
 #include "MsgDialog.hpp"
 #include "libslic3r/Preset.hpp"
 #include <algorithm>
diff --git a/src/slic3r/GUI/Field.hpp b/src/slic3r/GUI/Field.hpp
index da078d37a4..81a14be3ac 100644
--- a/src/slic3r/GUI/Field.hpp
+++ b/src/slic3r/GUI/Field.hpp
@@ -29,13 +29,17 @@
 
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Config.hpp"
-#include "libslic3r/Utils.hpp"
 
-#include "GUI.hpp"
 #include "wxExtensions.hpp"
 #include "Widgets/SpinInput.hpp"
-#include "Widgets/TextInput.hpp"
-#include "Widgets/ComboBox.hpp"
+
+class ComboBox;
+class TextInput;
+class wxBitmap;
+class wxBoxSizer;
+class wxCommandEvent;
+class wxEvent;
+class wxSizer;
 
 #ifdef __WXMSW__
 #define wxMSW true
diff --git a/src/slic3r/GUI/FilamentPickerDialog.cpp b/src/slic3r/GUI/FilamentPickerDialog.cpp
index 8821a43c52..b5e85ab72b 100644
--- a/src/slic3r/GUI/FilamentPickerDialog.cpp
+++ b/src/slic3r/GUI/FilamentPickerDialog.cpp
@@ -4,7 +4,6 @@
 #include "GUI_App.hpp"
 #include "MainFrame.hpp"
 #include "EncodedFilament.hpp"
-#include "Widgets/Label.hpp"
 #include "Widgets/Button.hpp"
 #include "Widgets/StateColor.hpp"
 #include "Widgets/DialogButtons.hpp"
diff --git a/src/slic3r/GUI/FileArchiveDialog.cpp b/src/slic3r/GUI/FileArchiveDialog.cpp
index 42fdc9a700..42ebbc1be8 100644
--- a/src/slic3r/GUI/FileArchiveDialog.cpp
+++ b/src/slic3r/GUI/FileArchiveDialog.cpp
@@ -2,10 +2,7 @@
 
 #include "I18N.hpp"
 #include "GUI_App.hpp"
-#include "GUI.hpp"
 #include "MainFrame.hpp"
-#include "ExtraRenderers.hpp"
-#include "format.hpp"
 #include <memory>
 #include <cassert>
 #include <miniz.h>
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index fd724022c0..3f099108f9 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -100,7 +100,6 @@
 #include "Mouse3DController.hpp"
 #include "I18N.hpp"
 #include "NotificationManager.hpp"
-#include "format.hpp"
 #include "DailyTips.hpp"
 #include "FilamentMapDialog.hpp"
 #include "Gizmos/GLGizmoUtils.hpp"
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 84fac13ff1..cf2a2aa96d 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -15,11 +15,8 @@
 #include "libslic3r/Technologies.hpp"
 #include "libslic3r/Model.hpp"
 #include "libvgcode/include/Types.hpp"
-#include "libvgcode/include/PathVertex.hpp"
-#include "libslic3r/Color.hpp"
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Line.hpp"
-#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
 #include <stddef.h>
 #include <memory>
 #include <chrono>
@@ -33,7 +30,6 @@
 #include "GUI_ObjectLayers.hpp"
 #include "GLSelectionRectangle.hpp"
 #include "MeshUtils.hpp"
-#include "libslic3r/GCode/GCodeProcessor.hpp"
 #include "GCodeViewer.hpp"
 #include "Camera.hpp"
 #include "SceneRaycaster.hpp"
@@ -55,6 +51,14 @@
 #include <wx/time.h>
 #include <wx/timer.h>
 
+namespace Slic3r { class ColorRGBA; }
+namespace Slic3r { class DynamicPrintConfig; }
+namespace Slic3r { class GLShaderProgram; }
+namespace Slic3r { struct GCodeProcessorResult; }
+namespace Slic3r::GUI { class ImGuiWrapper; }
+namespace libvgcode { struct PathVertex; }
+struct ImVec2;
+
 class wxSizeEvent;
 class wxIdleEvent;
 class wxKeyEvent;
diff --git a/src/slic3r/GUI/GUI.cpp b/src/slic3r/GUI/GUI.cpp
index 639905a31b..7de994960e 100644
--- a/src/slic3r/GUI/GUI.cpp
+++ b/src/slic3r/GUI/GUI.cpp
@@ -4,7 +4,6 @@
 #include "format.hpp"
 #include "I18N.hpp"
 
-#include "libslic3r/LocalesUtils.hpp"
 #include "libslic3r/Config.hpp"
 #include <memory>
 #include <vector>
diff --git a/src/slic3r/GUI/GUI_Factories.cpp b/src/slic3r/GUI/GUI_Factories.cpp
index 7913a33e7c..239e29ba41 100644
--- a/src/slic3r/GUI/GUI_Factories.cpp
+++ b/src/slic3r/GUI/GUI_Factories.cpp
@@ -14,7 +14,6 @@
 #include "OptionsGroup.hpp"
 #include "GLCanvas3D.hpp"
 #include "Selection.hpp"
-#include "format.hpp"
 //BBS: add partplate related logic
 #include "PartPlate.hpp"
 #include "Gizmos/GLGizmoEmboss.hpp"
diff --git a/src/slic3r/GUI/GUI_Init.cpp b/src/slic3r/GUI/GUI_Init.cpp
index 0eb2110b19..3806c25799 100644
--- a/src/slic3r/GUI/GUI_Init.cpp
+++ b/src/slic3r/GUI/GUI_Init.cpp
@@ -2,13 +2,10 @@
 
 #include "libslic3r/AppConfig.hpp"
 
-#include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
-#include "slic3r/GUI/3DScene.hpp"
 #include "slic3r/GUI/InstanceCheck.hpp"
 #include "slic3r/GUI/format.hpp"
 #include "slic3r/GUI/MainFrame.hpp"
-#include "slic3r/GUI/Plater.hpp"
 
 // To show a message box if GUI initialization ends up with an exception thrown.
 #include <vector>
@@ -17,7 +14,6 @@
 #include "libslic3r/Exception.hpp"
 #include <boost/log/trivial.hpp>
 #include <ostream>
-#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
 #include <exception>
 #include <wx/msgdlg.h>
 
diff --git a/src/slic3r/GUI/GUI_ObjectList.cpp b/src/slic3r/GUI/GUI_ObjectList.cpp
index 38633dc86a..1f3216eee6 100644
--- a/src/slic3r/GUI/GUI_ObjectList.cpp
+++ b/src/slic3r/GUI/GUI_ObjectList.cpp
@@ -51,7 +51,6 @@
 #include "libslic3r/Point.hpp"
 #include <boost/algorithm/string/predicate.hpp>
 #include "libslic3r/LocalesUtils.hpp"
-#include "libslic3r/Format/STEP.hpp"
 #include <exception>
 #include "slic3r/GUI/ParamsPanel.hpp"
 #include "slic3r/GUI/GUI_ObjectLayers.hpp"
@@ -103,6 +102,9 @@
 #include "Gizmos/GLGizmoScale.hpp"
 
 #include "libslic3r/TriangleMeshDeal.hpp"
+
+class wxMenu;
+namespace Slic3r { class Step; }
 namespace Slic3r
 {
 namespace GUI
diff --git a/src/slic3r/GUI/GUI_ObjectList.hpp b/src/slic3r/GUI/GUI_ObjectList.hpp
index 4aff69534e..df5fe92e04 100644
--- a/src/slic3r/GUI/GUI_ObjectList.hpp
+++ b/src/slic3r/GUI/GUI_ObjectList.hpp
@@ -20,11 +20,12 @@
 #include <wx/window.h>
 
 #include "Event.hpp"
-#include "wxExtensions.hpp"
 #include "ObjectDataViewModel.hpp"
 
 #include "libslic3r/PrintConfig.hpp"
 
+class wxBitmap;
+
 class wxBoxSizer;
 class wxBitmapComboBox;
 class wxMenuItem;
diff --git a/src/slic3r/GUI/GUI_ObjectTable.cpp b/src/slic3r/GUI/GUI_ObjectTable.cpp
index 03fa69fc1a..526592a5cc 100644
--- a/src/slic3r/GUI/GUI_ObjectTable.cpp
+++ b/src/slic3r/GUI/GUI_ObjectTable.cpp
@@ -1,20 +1,15 @@
 #include "wx/clipbrd.h"
 #include "wx/display.h"
 
-#include "SelectMachine.hpp"
 #include "I18N.hpp"
 
-#include "libslic3r/Utils.hpp"
 #include "libslic3r/PresetBundle.hpp"
 //#include "libslic3r/Model.hpp"
 //#include "Plater.hpp"
 #include "Widgets/Label.hpp"
 #include "GUI.hpp"
 #include "GUI_App.hpp"
-#include "MainFrame.hpp"
 #include "Tab.hpp"
-#include "format.hpp"
-#include "BitmapCache.hpp"
 #include "GUI_ObjectTable.hpp"
 #include "GUI_ObjectList.hpp"
 #include <wx/gdicmn.h>
diff --git a/src/slic3r/GUI/GUI_Preview.cpp b/src/slic3r/GUI/GUI_Preview.cpp
index 03e8ad9b81..79c884cd6a 100644
--- a/src/slic3r/GUI/GUI_Preview.cpp
+++ b/src/slic3r/GUI/GUI_Preview.cpp
@@ -4,7 +4,6 @@
 #include "IMSlider.hpp"
 #include "GUI_Preview.hpp"
 #include "GUI_App.hpp"
-#include "GUI.hpp"
 #include <wx/slider.h>
 #include <wx/gdicmn.h>
 #include <string>
@@ -21,19 +20,15 @@
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/ExPolygon.hpp"
 #include <cmath>
-#include "libvgcode/include/Types.hpp"
 #if ENABLE_OPENGL_AUTO_AA_SAMPLES
 #include "GUI_Init.hpp"
 #endif // ENABLE_OPENGL_AUTO_AA_SAMPLES
 #include "I18N.hpp"
-#include "3DScene.hpp"
 #include "BackgroundSlicingProcess.hpp"
 #include "OpenGLManager.hpp"
 #include "GLCanvas3D.hpp"
-#include "libslic3r/PresetBundle.hpp"
 #include "Plater.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
 
 #include <wx/listbook.h>
 #include <wx/notebook.h>
@@ -47,7 +42,6 @@
 
 // this include must follow the wxWidgets ones or it won't compile on Windows -> see http://trac.wxwidgets.org/ticket/2421
 #include "libslic3r/Print.hpp"
-#include "libslic3r/SLAPrint.hpp"
 #include "NotificationManager.hpp"
 #include "libslic3r/Model.hpp"
 #include "libslic3r/MultiMaterialSegmentation.hpp"
@@ -55,6 +49,9 @@
 #include "slic3r/GUI/PartPlate.hpp"
 #include "slic3r/GUI/Selection.hpp"
 
+class wxDropTarget;
+namespace libvgcode { enum class EViewType : uint8_t; }
+
 #ifdef _WIN32
 #include "BitmapComboBox.hpp"
 #endif
diff --git a/src/slic3r/GUI/GUI_Preview.hpp b/src/slic3r/GUI/GUI_Preview.hpp
index 3080b7a89a..1b9e0c5cd9 100644
--- a/src/slic3r/GUI/GUI_Preview.hpp
+++ b/src/slic3r/GUI/GUI_Preview.hpp
@@ -7,17 +7,19 @@
 #include <wx/event.h>
 #include <wx/panel.h>
 
-#include "libslic3r/Point.hpp"
 #include "libslic3r/CustomGCode.hpp"
 
 //BBS: add print base
-#include "libslic3r/PrintBase.hpp"
 
 #include <string>
-#include "libslic3r/GCode/GCodeProcessor.hpp"
-#include <slic3r/GUI/GCodeViewer.hpp>
 #include <wx/window.h>
 
+class wxDropTarget;
+class wxSizeEvent;
+class wxWindow;
+namespace Slic3r { class PrintBase; }
+namespace Slic3r { struct GCodeProcessorResult; }
+
 class wxGLCanvas;
 class wxBoxSizer;
 class wxStaticText;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp b/src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp
index 47d3040d4c..5ccd3ef369 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp
@@ -14,7 +14,6 @@
 #include "slic3r/GUI/CameraUtils.hpp"
 #include "slic3r/GUI/Jobs/EmbossJob.hpp"
 #include "slic3r/GUI/Jobs/CreateFontNameImageJob.hpp"
-#include "slic3r/GUI/Jobs/NotificationProgressIndicator.hpp"
 #include "slic3r/Utils/WxFontUtils.hpp"
 #include "slic3r/Utils/UndoRedo.hpp"
 #include "GLGizmoUtils.hpp"
@@ -24,10 +23,7 @@
 
 #include "libslic3r/Model.hpp"
 #include "libslic3r/Preset.hpp"
-#include "libslic3r/ClipperUtils.hpp" // union_ex
 #include "libslic3r/AppConfig.hpp"    // store/load font list
-#include "libslic3r/Format/OBJ.hpp" // load obj file for default object
-#include "libslic3r/BuildVolume.hpp"
 
 #include "imgui/imgui_stdlib.h" // using std::string for inputs
 #include <string>
@@ -1591,6 +1587,8 @@ void GLGizmoEmboss::draw_window(float x, float y)
 #include "slic3r/GUI/ImGuiWrapper.hpp"
 #include "slic3r/Utils/RaycastManager.hpp"
 
+namespace Slic3r::GUI { struct Camera; }
+
 void GLGizmoEmboss::draw_text_input()
 {
     auto create_range_text_prep = [&mng = m_style_manager, &text = m_text, &exist_unknown = m_text_contain_unknown_glyph]() {
diff --git a/src/slic3r/GUI/Gizmos/GLGizmoMeasure.hpp b/src/slic3r/GUI/Gizmos/GLGizmoMeasure.hpp
index 1d76810050..7035c07e39 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmoMeasure.hpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmoMeasure.hpp
@@ -7,7 +7,6 @@
 #include "slic3r/GUI/MeshUtils.hpp"
 #include "slic3r/GUI/I18N.hpp"
 #include "libslic3r/Measure.hpp"
-#include "libslic3r/Model.hpp"
 #include "libslic3r/Color.hpp"
 #include <string>
 #include <array>
@@ -15,13 +14,15 @@
 #include "slic3r/GUI/SceneRaycaster.hpp"
 #include <optional>
 #include <map>
-#include "slic3r/GUI/3DScene.hpp"
 #include <memory>
 #include <vector>
 #include <wx/event.h>
 #include <utility>
 #include <wx/string.h>
 
+namespace Slic3r { class GLVolume; }
+namespace Slic3r::GUI { class GLCanvas3D; }
+
 namespace Slic3r {
 
 enum class ModelVolumeType : int;
diff --git a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
index 079971a134..f8c65e9ac9 100644
--- a/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
+++ b/src/slic3r/GUI/Gizmos/GLGizmosManager.cpp
@@ -1,4 +1,3 @@
-#include "libslic3r/libslic3r.h"
 #include "GLGizmosManager.hpp"
 #include "slic3r/GUI/GLCanvas3D.hpp"
 #include "slic3r/GUI/3DScene.hpp"
@@ -56,9 +55,7 @@
 #include "slic3r/GUI/Gizmos/GLGizmoSketch.hpp"
 #endif
 
-#include "libslic3r/format.hpp"
 #include "libslic3r/Model.hpp"
-#include "libslic3r/PresetBundle.hpp"
 
 #include <boost/functional/hash.hpp>
 
diff --git a/src/slic3r/GUI/HMSPanel.cpp b/src/slic3r/GUI/HMSPanel.cpp
index c767c8613c..7d0146e243 100644
--- a/src/slic3r/GUI/HMSPanel.cpp
+++ b/src/slic3r/GUI/HMSPanel.cpp
@@ -3,8 +3,6 @@
 #include "slic3r/GUI/DeviceCore/DevHMS.h"
 #include <boost/log/trivial.hpp>
 #include <slic3r/GUI/Widgets/SideTools.hpp>
-#include <slic3r/GUI/Widgets/Label.hpp>
-#include <slic3r/GUI/I18N.hpp>
 #include <wx/event.h>
 #include <string>
 #include <wx/panel.h>
@@ -20,6 +18,8 @@
 #include "MainFrame.hpp"
 #include "Monitor.hpp"
 
+class wxWindow;
+
 namespace Slic3r {
 namespace GUI {
 
diff --git a/src/slic3r/GUI/HintNotification.cpp b/src/slic3r/GUI/HintNotification.cpp
index 2267918b5a..433a829c29 100644
--- a/src/slic3r/GUI/HintNotification.cpp
+++ b/src/slic3r/GUI/HintNotification.cpp
@@ -2,7 +2,6 @@
 #include "ImGuiWrapper.hpp"
 #include "format.hpp"
 #include "I18N.hpp"
-#include "GUI_ObjectList.hpp"
 #include "GLCanvas3D.hpp"
 #include "MainFrame.hpp"
 #include "Preferences.hpp"
diff --git a/src/slic3r/GUI/IMSlider.cpp b/src/slic3r/GUI/IMSlider.cpp
index 685fe78c05..dab0c229e2 100644
--- a/src/slic3r/GUI/IMSlider.cpp
+++ b/src/slic3r/GUI/IMSlider.cpp
@@ -1,5 +1,4 @@
 #include "IMSlider.hpp"
-#include "libslic3r/GCode.hpp"
 #include "GUI_App.hpp"
 #include "GUI.hpp"
 #include "NotificationManager.hpp"
@@ -24,7 +23,6 @@
 #include "slic3r/GUI/GUI_Utils.hpp"
 #include <set>
 #include <wx/string.h>
-#include "slic3r/GUI/Gizmos/GLGizmoBase.hpp"
 #include <cstring>
 #include <cctype>
 #include <cstdlib>
diff --git a/src/slic3r/GUI/ImGuiWrapper.cpp b/src/slic3r/GUI/ImGuiWrapper.cpp
index 41663d147e..5728ad5697 100644
--- a/src/slic3r/GUI/ImGuiWrapper.cpp
+++ b/src/slic3r/GUI/ImGuiWrapper.cpp
@@ -63,7 +63,6 @@
 #include "BitmapCache.hpp"
 #include "GUI_App.hpp"
 
-#include "../Utils/MacDarkMode.hpp"
 #include <nanosvg/nanosvg.h>
 #include <nanosvg/nanosvgrast.h>
 #include "OpenGLManager.hpp"
diff --git a/src/slic3r/GUI/ImageDPIFrame.cpp b/src/slic3r/GUI/ImageDPIFrame.cpp
index 655fa87633..83904fe650 100644
--- a/src/slic3r/GUI/ImageDPIFrame.cpp
+++ b/src/slic3r/GUI/ImageDPIFrame.cpp
@@ -10,9 +10,6 @@
 #include <wx/slider.h>
 #include <wx/dcmemory.h>
 #include "GUI_App.hpp"
-#include "Tab.hpp"
-#include "PartPlate.hpp"
-#include "I18N.hpp"
 #include "MainFrame.hpp"
 #include <chrono>
 #include <wx/string.h>
diff --git a/src/slic3r/GUI/KBShortcutsDialog.cpp b/src/slic3r/GUI/KBShortcutsDialog.cpp
index 903ce4c43a..260392a274 100644
--- a/src/slic3r/GUI/KBShortcutsDialog.cpp
+++ b/src/slic3r/GUI/KBShortcutsDialog.cpp
@@ -1,9 +1,6 @@
-#include "libslic3r/libslic3r.h"
 #include "KBShortcutsDialog.hpp"
 #include "I18N.hpp"
-#include "libslic3r/Utils.hpp"
 #include "GUI.hpp"
-#include "Notebook.hpp"
 #include <vector>
 #include "slic3r/GUI/Shortcuts.hpp"
 #include <wx/colour.h>
diff --git a/src/slic3r/GUI/MediaFilePanel.cpp b/src/slic3r/GUI/MediaFilePanel.cpp
index 23aff37f77..249db6c3d7 100644
--- a/src/slic3r/GUI/MediaFilePanel.cpp
+++ b/src/slic3r/GUI/MediaFilePanel.cpp
@@ -8,7 +8,6 @@
 #include "slic3r/Utils/NetworkAgent.hpp"
 #include "Plater.hpp"
 #include "Widgets/Button.hpp"
-#include "Widgets/SwitchButton.hpp"
 #include "Widgets/Label.hpp"
 #include "Printer/PrinterFileSystem.h"
 #include "MsgDialog.hpp"
diff --git a/src/slic3r/GUI/MediaPlayCtrl.cpp b/src/slic3r/GUI/MediaPlayCtrl.cpp
index d7a80a7823..f62426723e 100644
--- a/src/slic3r/GUI/MediaPlayCtrl.cpp
+++ b/src/slic3r/GUI/MediaPlayCtrl.cpp
@@ -12,7 +12,6 @@
 #include "libslic3r_version.h"
 #include "slic3r/Utils/NetworkAgent.hpp"
 #include "slic3r/Utils/NetworkAgentFactory.hpp"
-#include "libslic3r/Thread.hpp"
 #include "libslic3r/AppConfig.hpp"
 #include "I18N.hpp"
 #include "MsgDialog.hpp"
@@ -74,6 +73,8 @@
 #include <wx/clipbrd.h>
 #include "wx/evtloop.h"
 
+class wxImage;
+
 static std::map<int, std::string> error_messages = {
     {1, L("The device cannot handle more conversations. Please retry later.")},
     {2, L("Player is malfunctioning. Please reinstall the system player.")},
diff --git a/src/slic3r/GUI/ModelMall.cpp b/src/slic3r/GUI/ModelMall.cpp
index bae46f2dcd..66d26f1042 100644
--- a/src/slic3r/GUI/ModelMall.cpp
+++ b/src/slic3r/GUI/ModelMall.cpp
@@ -20,11 +20,12 @@
 #include <wx/statbox.h>
 #include "wx/evtloop.h"
 
-#include "libslic3r/Model.hpp"
 #include "MainFrame.hpp"
 #include "GUI_App.hpp"
 #include "Plater.hpp"
 
+namespace Slic3r::GUI { class Plater; }
+
 namespace Slic3r {
 namespace GUI {
     ModelMallDialog::ModelMallDialog(Plater* plater /*= nullptr*/)
diff --git a/src/slic3r/GUI/Monitor.cpp b/src/slic3r/GUI/Monitor.cpp
index b1e07ee775..2c800ecebb 100644
--- a/src/slic3r/GUI/Monitor.cpp
+++ b/src/slic3r/GUI/Monitor.cpp
@@ -1,5 +1,4 @@
 #include "Tab.hpp"
-#include "libslic3r/Utils.hpp"
 #include "libslic3r/Model.hpp"
 #include "libslic3r/AppConfig.hpp"
 #include "slic3r/Utils/bambu_networking.hpp"
@@ -44,8 +43,6 @@
 #include "GUI_ObjectList.hpp"
 #include "Plater.hpp"
 #include "MainFrame.hpp"
-#include "Widgets/Label.hpp"
-#include "format.hpp"
 #include "MediaPlayCtrl.h"
 #include "MediaFilePanel.h"
 #include "Plater.hpp"
diff --git a/src/slic3r/GUI/NativeCommands.cpp b/src/slic3r/GUI/NativeCommands.cpp
index cd983d7e47..e93a1a4635 100644
--- a/src/slic3r/GUI/NativeCommands.cpp
+++ b/src/slic3r/GUI/NativeCommands.cpp
@@ -24,7 +24,6 @@
 #include <functional>
 #include <initializer_list>
 #include <libslic3r/Model.hpp>
-#include <libslic3r/Utils.hpp>
 
 #include <algorithm>
 #include <cmath>
@@ -41,6 +40,8 @@
 #include <wx/string.h>
 #include <wx/utils.h>
 
+class wxWindow;
+
 namespace Slic3r { namespace GUI {
 
 namespace {
diff --git a/src/slic3r/GUI/Notebook.cpp b/src/slic3r/GUI/Notebook.cpp
index 54c188fa38..bc71322558 100644
--- a/src/slic3r/GUI/Notebook.cpp
+++ b/src/slic3r/GUI/Notebook.cpp
@@ -7,7 +7,6 @@
 #include "Widgets/Button.hpp"
 
 //BBS set font size
-#include "Widgets/Label.hpp"
 
 #include <wx/bookctrl.h>
 #include <cmath>
diff --git a/src/slic3r/GUI/OG_CustomCtrl.cpp b/src/slic3r/GUI/OG_CustomCtrl.cpp
index 890e85fa9f..0c2fada78c 100644
--- a/src/slic3r/GUI/OG_CustomCtrl.cpp
+++ b/src/slic3r/GUI/OG_CustomCtrl.cpp
@@ -4,7 +4,6 @@
 #include "Plater.hpp"
 #include "GUI_App.hpp"
 #include "MsgDialog.hpp"
-#include "libslic3r/AppConfig.hpp"
 
 #include <wx/gdicmn.h>
 #include <wx/panel.h>
@@ -27,9 +26,7 @@
 #include <algorithm>
 #include <wx/utils.h>
 #include <boost/algorithm/string/split.hpp>
-#include "libslic3r/Utils.hpp"
 #include "I18N.hpp"
-#include "format.hpp"
 #include <slic3r/GUI/Widgets/Label.hpp>
 #include <wx/validate.h>
 
diff --git a/src/slic3r/GUI/OG_CustomCtrl.hpp b/src/slic3r/GUI/OG_CustomCtrl.hpp
index c0ea80c172..906da83d89 100644
--- a/src/slic3r/GUI/OG_CustomCtrl.hpp
+++ b/src/slic3r/GUI/OG_CustomCtrl.hpp
@@ -8,7 +8,6 @@
 #include <cstddef>
 #include <vector>
 #include <wx/event.h>
-#include "slic3r/GUI/Field.hpp"
 #include <wx/sizer.h>
 #include <wx/stattext.h>
 #include <wx/settings.h>
@@ -20,10 +19,16 @@
 #include <wx/validate.h>
 
 #include "libslic3r/Config.hpp"
-#include "libslic3r/PrintConfig.hpp"
 
 #include "OptionsGroup.hpp"
-#include "I18N.hpp"
+
+class wxColour;
+class wxDC;
+class wxMouseEvent;
+class wxPaintEvent;
+class wxSizer;
+class wxWindow;
+namespace Slic3r::GUI { class Field; }
 
 // Translate the ifdef 
 #ifdef __WXOSX__
diff --git a/src/slic3r/GUI/ObjColorDialog.cpp b/src/slic3r/GUI/ObjColorDialog.cpp
index af5857de15..e45d97efba 100644
--- a/src/slic3r/GUI/ObjColorDialog.cpp
+++ b/src/slic3r/GUI/ObjColorDialog.cpp
@@ -17,14 +17,11 @@
 #include <sstream>
 //#include "libslic3r/FlushVolCalc.hpp"
 #include "ObjColorDialog.hpp"
-#include "BitmapCache.hpp"
-#include "GUI.hpp"//for ICON_SIZE
 #include "I18N.hpp"
 #include "GUI_App.hpp"
 #include "MsgDialog.hpp"
 #include "Widgets/Button.hpp"
 #include "MainFrame.hpp"
-#include "libslic3r/Config.hpp"
 #include "BitmapComboBox.hpp"
 #include "Widgets/ComboBox.hpp"
 #include "Widgets/DialogButtons.hpp"
@@ -53,6 +50,8 @@
 #include "libslic3r/TriangleMesh.hpp"
 #include "slic3r/GUI/Widgets/DropDown.hpp"
 #include "slic3r/GUI/Widgets/Label.hpp"
+
+class wxBitmap;
 using namespace Slic3r;
 using namespace Slic3r::GUI;
 
diff --git a/src/slic3r/GUI/ObjectDataViewModel.cpp b/src/slic3r/GUI/ObjectDataViewModel.cpp
index eea00e57e6..2028516f40 100644
--- a/src/slic3r/GUI/ObjectDataViewModel.cpp
+++ b/src/slic3r/GUI/ObjectDataViewModel.cpp
@@ -1,5 +1,4 @@
 #include "ObjectDataViewModel.hpp"
-#include "slic3r/GUI/wxExtensions.hpp"
 #include "wxExtensions.hpp"
 #include "BitmapCache.hpp"
 #include "GUI_App.hpp"
diff --git a/src/slic3r/GUI/OptionsGroup.cpp b/src/slic3r/GUI/OptionsGroup.cpp
index 1a60b0e155..27cdf31050 100644
--- a/src/slic3r/GUI/OptionsGroup.cpp
+++ b/src/slic3r/GUI/OptionsGroup.cpp
@@ -1,5 +1,4 @@
 #include "OptionsGroup.hpp"
-#include "ConfigExceptions.hpp"
 #include "Plater.hpp"
 #include "SettingsIndex.hpp"
 #include "GUI_App.hpp"
@@ -7,7 +6,6 @@
 #include "OG_CustomCtrl.hpp"
 #include "MsgDialog.hpp"
 #include "PluginPickerDialog.hpp"
-#include "format.hpp"
 #include "Widgets/StaticLine.hpp"
 #include "Widgets/LabeledStaticBox.hpp"
 
@@ -34,8 +32,6 @@
 #include <boost/algorithm/string/split.hpp>
 #include <boost/algorithm/string/classification.hpp>
 #include "libslic3r/Exception.hpp"
-#include "libslic3r/Utils.hpp"
-#include "libslic3r/AppConfig.hpp"
 #include "slic3r/plugin/PluginManager.hpp"
 #include "I18N.hpp"
 #include <algorithm>
diff --git a/src/slic3r/GUI/ParamsDialog.cpp b/src/slic3r/GUI/ParamsDialog.cpp
index 1c0da2919c..cfd36c6643 100644
--- a/src/slic3r/GUI/ParamsDialog.cpp
+++ b/src/slic3r/GUI/ParamsDialog.cpp
@@ -1,12 +1,9 @@
 #include "ParamsDialog.hpp"
-#include "I18N.hpp"
 #include "ParamsPanel.hpp"
 #include "GUI_App.hpp"
-#include "MainFrame.hpp"
 #include "Plater.hpp"
 #include "Tab.hpp"
 
-#include "libslic3r/Utils.hpp"
 #include "slic3r/GUI/GUI_Utils.hpp"
 #include "libslic3r/Preset.hpp"
 #include <wx/wx.h>
@@ -19,6 +16,8 @@
 #include <wx/utils.h>
 #include "slic3r/GUI/Event.hpp"
 
+class wxWindow;
+
 namespace pt = boost::property_tree;
 typedef pt::ptree JSON;
 
diff --git a/src/slic3r/GUI/ParamsPanel.cpp b/src/slic3r/GUI/ParamsPanel.cpp
index 674bbcd54f..c367e4cb94 100644
--- a/src/slic3r/GUI/ParamsPanel.cpp
+++ b/src/slic3r/GUI/ParamsPanel.cpp
@@ -8,7 +8,6 @@
 #include "libslic3r/Preset.hpp"
 #include "ParamsPanel.hpp"
 #include "Tab.hpp"
-#include "format.hpp"
 #include "MainFrame.hpp"
 #include "GUI_App.hpp"
 #include "Plater.hpp"
@@ -26,7 +25,6 @@
 #include <wx/toplevel.h>
 #include <wx/sizer.h>
 #include <wx/panel.h>
-#include "slic3r/GUI/Field.hpp"
 #include "slic3r/GUI/Widgets/CheckBox.hpp"
 #include <wx/tglbtn.h>
 #include <wx/event.h>
diff --git a/src/slic3r/GUI/PartSkipDialog.cpp b/src/slic3r/GUI/PartSkipDialog.cpp
index a423802a6c..ddf0d10965 100644
--- a/src/slic3r/GUI/PartSkipDialog.cpp
+++ b/src/slic3r/GUI/PartSkipDialog.cpp
@@ -54,11 +54,9 @@
 #include "Widgets/CheckBox.hpp"
 #include "Widgets/Label.hpp"
 
-#include "MsgDialog.hpp"
 #include "Printer/PrinterFileSystem.h"
 #include "PartSkipDialog.hpp"
 #include "SkipPartCanvas.hpp"
-#include "MediaPlayCtrl.h"
 
 #include "DeviceCore/DevManager.h"
 
diff --git a/src/slic3r/GUI/PhysicalPrinterDialog.cpp b/src/slic3r/GUI/PhysicalPrinterDialog.cpp
index ffbf98ede2..212e94f133 100644
--- a/src/slic3r/GUI/PhysicalPrinterDialog.cpp
+++ b/src/slic3r/GUI/PhysicalPrinterDialog.cpp
@@ -42,7 +42,6 @@
 #include <wx/toplevel.h>
 #include <wx/wupdlock.h>
 
-#include "libslic3r/libslic3r.h"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/PresetBundle.hpp"
 
@@ -51,17 +50,12 @@
 #include "GUI.hpp"
 #include "GUI_App.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
 #include "Tab.hpp"
 #include "libslic3r_version.h"
-#include "wxExtensions.hpp"
 #include "PrintHostDialogs.hpp"
-#include "../Utils/ASCIIFolding.hpp"
 #include "../Utils/PrintHost.hpp"
 #include "../Utils/Flashforge.hpp"
 #include "../Utils/UndoRedo.hpp"
-#include "RemovableDriveManager.hpp"
-#include "BitmapCache.hpp"
 #include "BonjourDialog.hpp"
 #include "CrealityDiscoveryDialog.hpp"
 #include "MsgDialog.hpp"
diff --git a/src/slic3r/GUI/PresetComboBoxes.cpp b/src/slic3r/GUI/PresetComboBoxes.cpp
index 28dfbed4a8..3dfd5e3b0a 100644
--- a/src/slic3r/GUI/PresetComboBoxes.cpp
+++ b/src/slic3r/GUI/PresetComboBoxes.cpp
@@ -52,7 +52,6 @@
 #include <wx/msw/private.h>
 #endif
 
-#include "libslic3r/libslic3r.h"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/PresetBundle.hpp"
 #include "libslic3r/Color.hpp"
@@ -64,9 +63,7 @@
 #include "format.hpp"
 #include "Tab.hpp"
 #include "ConfigWizard.hpp"
-#include "../Utils/ASCIIFolding.hpp"
 #include "../Utils/UndoRedo.hpp"
-#include "../Utils/ColorSpaceConvert.hpp"
 #include "BitmapCache.hpp"
 #include "SavePresetDialog.hpp"
 #include "MsgDialog.hpp"
diff --git a/src/slic3r/GUI/PrinterWebView.cpp b/src/slic3r/GUI/PrinterWebView.cpp
index 7d849da5fd..e96d8c9062 100644
--- a/src/slic3r/GUI/PrinterWebView.cpp
+++ b/src/slic3r/GUI/PrinterWebView.cpp
@@ -1,9 +1,7 @@
 #include "PrinterWebView.hpp"
 
-#include "I18N.hpp"
 #include "PrinterWebViewHandler.hpp"
 #include "slic3r/GUI/PrinterWebView.hpp"
-#include "slic3r/GUI/wxExtensions.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/MainFrame.hpp"
 #include "libslic3r_version.h"
@@ -25,6 +23,8 @@
 #include <wx/utils.h>
 #include <wx/webview.h>
 
+class wxWindow;
+
 #ifdef __linux__
 #include <webkit2/webkit2.h>
 #endif
diff --git a/src/slic3r/GUI/ReleaseNote.cpp b/src/slic3r/GUI/ReleaseNote.cpp
index 42e6c4437b..9a0bc54b6e 100644
--- a/src/slic3r/GUI/ReleaseNote.cpp
+++ b/src/slic3r/GUI/ReleaseNote.cpp
@@ -3,16 +3,11 @@
 
 #include "bambu_networking.hpp"
 #include "libslic3r/Utils.hpp"
-#include "libslic3r/Thread.hpp"
 #include "GUI.hpp"
 #include "GUI_App.hpp"
 #include "GUI_Utils.hpp"
 #include "GUI_Preview.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
-#include "Widgets/ProgressDialog.hpp"
-#include "Widgets/RoundedRectangle.hpp"
-#include "Widgets/StaticBox.hpp"
 #include "Widgets/WebView.hpp"
 #include "Jobs/BoostThreadWorker.hpp"
 #include "Jobs/PlaterWorker.hpp"
@@ -63,7 +58,6 @@
 #include <wx/webrequest.h>
 #include <wx/timer.h>
 #include "Plater.hpp"
-#include "BitmapCache.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 
 #include "DeviceCore/DevManager.h"
@@ -80,6 +74,8 @@
 #include "slic3r/Utils/NetworkAgent.hpp"
 #include <boost/filesystem.hpp>
 
+namespace Slic3r::GUI { class Plater; }
+
 namespace fs = boost::filesystem;
 
 namespace Slic3r { namespace GUI {
diff --git a/src/slic3r/GUI/SelectMachine.cpp b/src/slic3r/GUI/SelectMachine.cpp
index 3135c038b9..36b12017c5 100644
--- a/src/slic3r/GUI/SelectMachine.cpp
+++ b/src/slic3r/GUI/SelectMachine.cpp
@@ -9,7 +9,6 @@
 #include "GUI_App.hpp"
 #include "GUI_Preview.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
 #include "Widgets/ProgressDialog.hpp"
 #include "Widgets/RoundedRectangle.hpp"
 #include "Widgets/StaticBox.hpp"
@@ -134,6 +133,8 @@
 #include "slic3r/Utils/NetworkAgent.hpp"
 #include <boost/filesystem.hpp>
 
+namespace Slic3r { class PrintBase; }
+
 namespace fs = boost::filesystem;
 
 namespace Slic3r { namespace GUI {
diff --git a/src/slic3r/GUI/SelectMachinePop.cpp b/src/slic3r/GUI/SelectMachinePop.cpp
index 6dc39bb1a0..7a847ec9d0 100644
--- a/src/slic3r/GUI/SelectMachinePop.cpp
+++ b/src/slic3r/GUI/SelectMachinePop.cpp
@@ -10,7 +10,6 @@
 #include "GUI_App.hpp"
 #include "GUI_Preview.hpp"
 #include "MainFrame.hpp"
-#include "format.hpp"
 #include "Widgets/ProgressDialog.hpp"
 #include "Widgets/RoundedRectangle.hpp"
 #include "Widgets/StaticBox.hpp"
@@ -53,7 +52,6 @@
 #include <wx/string.h>
 #include "Plater.hpp"
 #include "Notebook.hpp"
-#include "BitmapCache.hpp"
 #include "BindDialog.hpp"
 
 #include "DeviceCore/DevManager.h"
diff --git a/src/slic3r/GUI/SendSystemInfoDialog.cpp b/src/slic3r/GUI/SendSystemInfoDialog.cpp
index 3c16ddde93..0329222f22 100644
--- a/src/slic3r/GUI/SendSystemInfoDialog.cpp
+++ b/src/slic3r/GUI/SendSystemInfoDialog.cpp
@@ -45,11 +45,9 @@
 
 #include "slic3r/GUI/format.hpp"
 #include "slic3r/Utils/Http.hpp"
-#include "slic3r/Utils/PresetUpdater.hpp"
 
 #include "GUI_App.hpp"
 #include "GUI_Utils.hpp"
-#include "I18N.hpp"
 #ifdef __WXGTK__
 #include "LinuxDisplayBackend.hpp"
 #endif
@@ -75,6 +73,8 @@
 #include <atomic>
 #include <thread>
 
+class wxWindow;
+
 #ifdef _WIN32
     #include <windows.h>
     #include <netlistmgr.h>
diff --git a/src/slic3r/GUI/StatusPanel.cpp b/src/slic3r/GUI/StatusPanel.cpp
index a1f2b72c1a..fa199ddf19 100644
--- a/src/slic3r/GUI/StatusPanel.cpp
+++ b/src/slic3r/GUI/StatusPanel.cpp
@@ -14,7 +14,6 @@
 #include "MsgDialog.hpp"
 #include "bambu_networking.hpp"
 #include "slic3r/Utils/Http.hpp"
-#include "libslic3r/Thread.hpp"
 #include "DeviceErrorDialog.hpp"
 
 #include "RecenterDialog.hpp"
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index 3050830d56..770e14de9f 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -103,13 +103,11 @@
 #include "Widgets/SwitchButton.hpp"
 #include "Widgets/TabCtrl.hpp"
 #include "Widgets/ComboBox.hpp"
-#include "MarkdownTip.hpp"
 #include "Search.hpp"
 #include "BedShapeDialog.hpp"
 #include "libslic3r/GCode/Thumbnails.hpp"
 #include "WipeTowerDialog.hpp"
 
-#include "DeviceCore/DevManager.h"
 
 #ifdef WIN32
 	#include <commctrl.h>
diff --git a/src/slic3r/GUI/ThermalPreconditioningDialog.cpp b/src/slic3r/GUI/ThermalPreconditioningDialog.cpp
index 03a0c5f45f..d6a04ddbd6 100644
--- a/src/slic3r/GUI/ThermalPreconditioningDialog.cpp
+++ b/src/slic3r/GUI/ThermalPreconditioningDialog.cpp
@@ -1,8 +1,6 @@
 #include "ThermalPreconditioningDialog.hpp"
 #include "I18N.hpp"
-#include "GUI.hpp"
 #include "GUI_App.hpp"
-#include "wxExtensions.hpp"
 #include "DeviceManager.hpp"
 #include "DeviceCore/DevManager.h"
 #include <wx/wx.h>
@@ -17,6 +15,8 @@
 #include <wx/font.h>
 #include <wx/event.h>
 
+class wxWindow;
+
 namespace Slic3r { namespace GUI {
 
 BEGIN_EVENT_TABLE(ThermalPreconditioningDialog, wxDialog)
diff --git a/src/slic3r/GUI/UVEditorCanvas.cpp b/src/slic3r/GUI/UVEditorCanvas.cpp
index 3a2b28a689..03a642fc07 100644
--- a/src/slic3r/GUI/UVEditorCanvas.cpp
+++ b/src/slic3r/GUI/UVEditorCanvas.cpp
@@ -45,7 +45,6 @@
 #include "Widgets/CheckBox.hpp"
 #include "Widgets/SpinInput.hpp"
 #include "libslic3r/AppConfig.hpp"
-#include "libslic3r/Utils.hpp"
 
 namespace Slic3r::GUI {
 
diff --git a/src/slic3r/GUI/WebGuideDialog.cpp b/src/slic3r/GUI/WebGuideDialog.cpp
index b631f5094e..5c79dc8115 100644
--- a/src/slic3r/GUI/WebGuideDialog.cpp
+++ b/src/slic3r/GUI/WebGuideDialog.cpp
@@ -12,7 +12,6 @@
 #include <boost/filesystem/path.hpp>
 #include <boost/iostreams/detail/select.hpp>
 #include <boost/log/trivial.hpp>
-#include "slic3r/GUI/Printer/PrinterFileSystem.h"
 #include <map>
 #include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/GUI_Utils.hpp"
@@ -36,7 +35,6 @@
 #include "libslic3r/Preset.hpp"
 #include "libslic3r/PresetBundle.hpp"
 #include "libslic3r/PresetCacheFormat.hpp"
-#include "slic3r/GUI/wxExtensions.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "libslic3r_version.h"
 
@@ -74,8 +72,6 @@
 #include "Plater.hpp"
 #include <boost/dll.hpp>
 #include <slic3r/GUI/Widgets/WebView.hpp>
-#include <slic3r/Utils/Http.hpp>
-#include <libslic3r/miniz_extension.hpp>
 #include <libslic3r/Utils.hpp>
 #include "CreatePresetsDialog.hpp"
 #include "libslic3r/PrintConfig.hpp"
@@ -83,6 +79,8 @@
 #include "slic3r/Utils/PresetUpdater.hpp"
 #include "slic3r/Utils/json_diff.hpp"
 
+class wxWindow;
+
 namespace fs = boost::filesystem;
 
 using namespace nlohmann;
diff --git a/src/slic3r/GUI/WebViewDialog.cpp b/src/slic3r/GUI/WebViewDialog.cpp
index 3e36a6be09..7a119c440d 100644
--- a/src/slic3r/GUI/WebViewDialog.cpp
+++ b/src/slic3r/GUI/WebViewDialog.cpp
@@ -2,11 +2,9 @@
 
 #include "CloudProvider.hpp"
 #include "I18N.hpp"
-#include "slic3r/GUI/wxExtensions.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/MainFrame.hpp"
 #include "libslic3r_version.h"
-#include "../Utils/Http.hpp"
 
 #include <boost/filesystem/path.hpp>
 #include <boost/log/trivial.hpp>
diff --git a/src/slic3r/GUI/Widgets/AMSItem.cpp b/src/slic3r/GUI/Widgets/AMSItem.cpp
index c686bf8c24..e367930db1 100644
--- a/src/slic3r/GUI/Widgets/AMSItem.cpp
+++ b/src/slic3r/GUI/Widgets/AMSItem.cpp
@@ -1,6 +1,5 @@
 #include "AMSItem.hpp"
 #include "Label.hpp"
-#include "../BitmapCache.hpp"
 #include "../I18N.hpp"
 #include "../GUI_App.hpp"
 #include "../FilamentBitmapUtils.hpp"
@@ -15,7 +14,6 @@
 #include <wx/anybutton.h>
 #include <wx/colour.h>
 #include <wx/event.h>
-#include "slic3r/GUI/Event.hpp"
 #include <string>
 #include "slic3r/GUI/DeviceCore/DevDefs.h"
 #include "slic3r/GUI/DeviceCore/DevFilaSwitch.h"
@@ -47,6 +45,8 @@
 #include "CalibUtils.hpp"
 #include "slic3r/GUI/wxExtensions.hpp"
 
+namespace Slic3r::GUI { struct SimpleEvent; }
+
 
 
 namespace Slic3r { namespace GUI {
diff --git a/src/slic3r/GUI/Widgets/FanControl.cpp b/src/slic3r/GUI/Widgets/FanControl.cpp
index e4f039307b..adb440d876 100644
--- a/src/slic3r/GUI/Widgets/FanControl.cpp
+++ b/src/slic3r/GUI/Widgets/FanControl.cpp
@@ -1,6 +1,5 @@
 #include "FanControl.hpp"
 #include "Label.hpp"
-#include "../BitmapCache.hpp"
 #include "../I18N.hpp"
 #include "../GUI_App.hpp"
 #include "../MsgDialog.hpp"
diff --git a/src/slic3r/GUI/Widgets/ProgressBar.cpp b/src/slic3r/GUI/Widgets/ProgressBar.cpp
index 86963fa638..ac134a5364 100644
--- a/src/slic3r/GUI/Widgets/ProgressBar.cpp
+++ b/src/slic3r/GUI/Widgets/ProgressBar.cpp
@@ -1,5 +1,4 @@
 #include "ProgressBar.hpp"
-#include "../I18N.hpp"
 #include <wx/dc.h>
 #include <wx/dcclient.h>
 #include <wx/dcgraph.h>
diff --git a/src/slic3r/GUI/Widgets/ProgressDialog.hpp b/src/slic3r/GUI/Widgets/ProgressDialog.hpp
index a8b2dee827..e151428b84 100644
--- a/src/slic3r/GUI/Widgets/ProgressDialog.hpp
+++ b/src/slic3r/GUI/Widgets/ProgressDialog.hpp
@@ -5,8 +5,6 @@
 #include "wx/progdlg.h"
 #include "wx/weakref.h"
 #include "wx/simplebook.h"
-#include "Button.hpp"
-#include "../wxExtensions.hpp"
 #include <wx/dlimpexp.h>
 #include <wx/string.h>
 #include <cstddef>
@@ -14,6 +12,17 @@
 #include <wx/panel.h>
 #include <wx/translation.h>
 
+class Button;
+class wxCloseEvent;
+class wxCommandEvent;
+class wxPaintEvent;
+class wxPanel;
+class wxScrolledWindow;
+class wxSimplebook;
+class wxSizer;
+class wxWindow;
+namespace Slic3r::GUI { class ProgressDialog; }
+
 class WXDLLIMPEXP_FWD_CORE wxButton;
 class WXDLLIMPEXP_FWD_CORE wxEventLoop;
 class WXDLLIMPEXP_FWD_CORE wxGauge;
diff --git a/src/slic3r/GUI/Widgets/SideMenuPopup.cpp b/src/slic3r/GUI/Widgets/SideMenuPopup.cpp
index 3a55475e60..2d3945b050 100644
--- a/src/slic3r/GUI/Widgets/SideMenuPopup.cpp
+++ b/src/slic3r/GUI/Widgets/SideMenuPopup.cpp
@@ -1,5 +1,4 @@
 #include "SideMenuPopup.hpp"
-#include "Label.hpp"
 
 #include "slic3r/GUI/Widgets/PopupWindow.hpp"
 #include <algorithm>
diff --git a/src/slic3r/GUI/Widgets/TempInput.cpp b/src/slic3r/GUI/Widgets/TempInput.cpp
index 5890c702ac..d75d8cecd7 100644
--- a/src/slic3r/GUI/Widgets/TempInput.cpp
+++ b/src/slic3r/GUI/Widgets/TempInput.cpp
@@ -18,7 +18,6 @@
 #include <wx/textctrl.h>
 #include <wx/sizer.h>
 #include <wx/panel.h>
-#include "../GUI.hpp"
 #include "../GUI_App.hpp"
 
 wxDEFINE_EVENT(wxCUSTOMEVT_SET_TEMP_FINISH, wxCommandEvent);
diff --git a/src/slic3r/GUI/Widgets/TextInput.cpp b/src/slic3r/GUI/Widgets/TextInput.cpp
index 40131129d4..356ce626a5 100644
--- a/src/slic3r/GUI/Widgets/TextInput.cpp
+++ b/src/slic3r/GUI/Widgets/TextInput.cpp
@@ -1,5 +1,4 @@
 #include "TextInput.hpp"
-#include "Label.hpp"
 #include "TextCtrl.h"
 #include "slic3r/GUI/Widgets/Label.hpp"
 
diff --git a/src/slic3r/GUI/WipeTowerDialog.cpp b/src/slic3r/GUI/WipeTowerDialog.cpp
index 001eb91149..2ce6867db5 100644
--- a/src/slic3r/GUI/WipeTowerDialog.cpp
+++ b/src/slic3r/GUI/WipeTowerDialog.cpp
@@ -11,7 +11,6 @@
 #include "slic3r/GUI/Widgets/SpinInput.hpp"
 #include <cstddef>
 #include "libslic3r/PrintConfig.hpp"
-#include "slic3r/GUI/Printer/PrinterFileSystem.h"
 #include "slic3r/GUI/Plater.hpp"
 #include "libslic3r/FlushVolPredictor.hpp"
 #include "libslic3r/Utils.hpp"
@@ -31,10 +30,8 @@
 #include "GUI.hpp"
 #include "I18N.hpp"
 #include "GUI_App.hpp"
-#include "WebViewDialog.hpp"
 #include "MsgDialog.hpp"
 #include "format.hpp"
-#include "libslic3r/Color.hpp"
 #include "Widgets/StaticLine.hpp"
 #include "Widgets/DialogButtons.hpp"
 #include "libslic3r/Config.hpp"
@@ -45,6 +42,8 @@
 #include "slic3r/Utils/json_diff.hpp"
 #include <boost/filesystem.hpp>
 
+class wxWindow;
+
 namespace fs = boost::filesystem;
 
 using namespace Slic3r;
diff --git a/src/slic3r/GUI/wxExtensions.cpp b/src/slic3r/GUI/wxExtensions.cpp
index 26b03a028b..ef77b714f0 100644
--- a/src/slic3r/GUI/wxExtensions.cpp
+++ b/src/slic3r/GUI/wxExtensions.cpp
@@ -36,7 +36,6 @@
 #include "I18N.hpp"
 #include "GUI_Utils.hpp"
 #include "Plater.hpp"
-#include "../Utils/MacDarkMode.hpp"
 #include "BitmapComboBox.hpp"
 #include "Widgets/StaticBox.hpp"
 #include "Widgets/Label.hpp"
diff --git a/src/slic3r/GUI/wxMediaCtrl3.cpp b/src/slic3r/GUI/wxMediaCtrl3.cpp
index 67bf5cf9a3..31a8df55d7 100644
--- a/src/slic3r/GUI/wxMediaCtrl3.cpp
+++ b/src/slic3r/GUI/wxMediaCtrl3.cpp
@@ -1,7 +1,5 @@
 #include "wxMediaCtrl3.h"
 #include "AVVideoDecoder.hpp"
-#include "I18N.hpp"
-#include "libslic3r/Utils.hpp"
 #include <algorithm>
 #include <boost/log/trivial.hpp>
 #include "slic3r/GUI/Printer/BambuTunnel.h"
@@ -23,6 +21,8 @@
 extern "C" {
 #include <libavformat/avformat.h>
 #include <libavutil/log.h>
+
+class wxWindow;
 }
 #ifdef __WIN32__
 #include <versionhelpers.h>
diff --git a/src/slic3r/Utils/BBLCloudServiceAgent.cpp b/src/slic3r/Utils/BBLCloudServiceAgent.cpp
index 3ecf247dcc..96525354e5 100644
--- a/src/slic3r/Utils/BBLCloudServiceAgent.cpp
+++ b/src/slic3r/Utils/BBLCloudServiceAgent.cpp
@@ -3,7 +3,6 @@
 
 #include <boost/log/trivial.hpp>
 #include "CloudProvider.hpp"
-#include "Http.hpp"
 #include "bambu_networking.hpp"
 #include "ICloudServiceAgent.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
diff --git a/src/slic3r/Utils/CrealityPrint.cpp b/src/slic3r/Utils/CrealityPrint.cpp
index 20e702ba54..8a187ff998 100644
--- a/src/slic3r/Utils/CrealityPrint.cpp
+++ b/src/slic3r/Utils/CrealityPrint.cpp
@@ -41,7 +41,6 @@
 #include "slic3r/GUI/format.hpp"
 #include "Http.hpp"
 #include "libslic3r/AppConfig.hpp"
-#include "Bonjour.hpp"
 #include "slic3r/GUI/BonjourDialog.hpp"
 
 #include <boost/beast/core.hpp>
diff --git a/src/slic3r/Utils/ElegooLink.hpp b/src/slic3r/Utils/ElegooLink.hpp
index 9072fd5c78..1cd471caf7 100644
--- a/src/slic3r/Utils/ElegooLink.hpp
+++ b/src/slic3r/Utils/ElegooLink.hpp
@@ -10,9 +10,10 @@
 #include <boost/asio/ip/address.hpp>
 
 #include "PrintHost.hpp"
-#include "libslic3r/PrintConfig.hpp"
 #include "OctoPrint.hpp"
-#include "WebSocketClient.hpp"
+
+class WebSocketClient;
+namespace boost { template <class T> class optional; }
 namespace Slic3r {
 
 class DynamicPrintConfig;
diff --git a/src/slic3r/Utils/Moonraker.cpp b/src/slic3r/Utils/Moonraker.cpp
index f8692a8bb8..ee437595ef 100644
--- a/src/slic3r/Utils/Moonraker.cpp
+++ b/src/slic3r/Utils/Moonraker.cpp
@@ -14,7 +14,6 @@
 #include "PrintHost.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/I18N.hpp"
-#include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/format.hpp"
 #include "Http.hpp"
 
diff --git a/src/slic3r/Utils/Obico.cpp b/src/slic3r/Utils/Obico.cpp
index 9dabd91467..37a618445a 100644
--- a/src/slic3r/Utils/Obico.cpp
+++ b/src/slic3r/Utils/Obico.cpp
@@ -28,7 +28,6 @@
 #include "slic3r/GUI/format.hpp"
 #include "Http.hpp"
 #include "libslic3r/AppConfig.hpp"
-#include "Bonjour.hpp"
 #include "slic3r/GUI/BonjourDialog.hpp"
 
 namespace fs = boost::filesystem;
diff --git a/src/slic3r/Utils/PresetUpdater.cpp b/src/slic3r/Utils/PresetUpdater.cpp
index 1df0edf8fa..90807eb723 100644
--- a/src/slic3r/Utils/PresetUpdater.cpp
+++ b/src/slic3r/Utils/PresetUpdater.cpp
@@ -39,7 +39,6 @@
 #include <wx/msgdlg.h>
 
 #include "json_diff.hpp"
-#include "libslic3r/libslic3r.h"
 #include "libslic3r/format.hpp"
 #include "libslic3r/Utils.hpp"
 #include "libslic3r/PresetBundle.hpp"
@@ -49,7 +48,6 @@
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/I18N.hpp"
 #include "slic3r/GUI/UpdateDialogs.hpp"
-#include "slic3r/GUI/ConfigWizard.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/Plater.hpp"
 #include "slic3r/GUI/format.hpp"
@@ -57,10 +55,11 @@
 #include "slic3r/Utils/Http.hpp"
 #include "slic3r/Utils/bambu_networking.hpp"
 #include "slic3r/Config/Version.hpp"
-#include "slic3r/Config/Snapshot.hpp"
 #include "slic3r/GUI/MarkdownTip.hpp"
 #include "libslic3r/miniz_extension.hpp"
-#include "slic3r/GUI/GUI_Utils.hpp"
+
+namespace Slic3r::GUI::Config { class Snapshot; }
+namespace Slic3r::GUI::Config { class SnapshotDB; }
 
 namespace fs = boost::filesystem;
 using Slic3r::GUI::Config::Index;
diff --git a/src/slic3r/Utils/UltiMaker.cpp b/src/slic3r/Utils/UltiMaker.cpp
index fefd8ec786..432725f0e8 100644
--- a/src/slic3r/Utils/UltiMaker.cpp
+++ b/src/slic3r/Utils/UltiMaker.cpp
@@ -29,7 +29,6 @@
 #include "libslic3r/PrintConfig.hpp"
 #include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/I18N.hpp"
-#include "slic3r/GUI/MsgDialog.hpp"
 #include "Http.hpp"
 
 #include <iostream>
diff --git a/tests/fff_print/test_print.cpp b/tests/fff_print/test_print.cpp
index ca607a7c83..40f6343d95 100644
--- a/tests/fff_print/test_print.cpp
+++ b/tests/fff_print/test_print.cpp
@@ -24,7 +24,6 @@
 
 #include <catch2/catch_all.hpp>
 
-#include "libslic3r/libslic3r.h"
 #include "libslic3r/Print.hpp"
 #include "libslic3r/Layer.hpp"
 #include "libslic3r/Model.hpp"
diff --git a/tests/slic3rutils/test_network_versions.cpp b/tests/slic3rutils/test_network_versions.cpp
index bfddcb5423..ad352e0bfa 100644
--- a/tests/slic3rutils/test_network_versions.cpp
+++ b/tests/slic3rutils/test_network_versions.cpp
@@ -8,7 +8,6 @@
 #include <cstddef>
 
 #include <catch2/catch_test_macros.hpp>
-#include "libslic3r/Utils.hpp"
 #include "slic3r/Utils/bambu_networking.hpp"
 
 #include "plugin_test_utils.hpp"