diff --git a/.clang-tidy b/.clang-tidy
index f45561badb..3f0aaa8bde 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -14,7 +14,9 @@ CheckOptions:
   # admesh's stl.h, which the include path also exposes without its directory.
   # Clipper's own clipper.hpp is only included through libslic3r/clipper.hpp or
   # clipper_z.hpp, which configure it first, and Boost.Polygon's headers only
-  # work through boost/polygon/polygon.hpp or voronoi.hpp. minilzo's config
+  # work through boost/polygon/polygon.hpp or voronoi.hpp. Clipper2's headers
+  # are included through clipper2/clipper.h, or clipper2_z.hpp, which defines
+  # USINGZ first. minilzo's config
   # headers are internal to minilzo.h.
   # FFmpeg's C headers are left alone because they are only included inside
   # extern "C", which an inserted include would miss. OS-specific headers (GLib,
@@ -59,4 +61,5 @@ CheckOptions:
     png(lib)?conf\.h;
     mcut[/\\]platform\.h;
     boost[/\\]polygon[/\\].*;
+    clipper2[/\\]clipper\.(core|engine|offset|minkowski|rectclip|export|triangulation|version)\.h;
     lzo(conf|defs)\.h
diff --git a/src/libslic3r/Algorithm/LineSplit.cpp b/src/libslic3r/Algorithm/LineSplit.cpp
index 5b084861d2..789ca39be6 100644
--- a/src/libslic3r/Algorithm/LineSplit.cpp
+++ b/src/libslic3r/Algorithm/LineSplit.cpp
@@ -1,6 +1,7 @@
 #include "LineSplit.hpp"
 
 #include "AABBTreeLines.hpp"
+#include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/ClipperZUtils.hpp"
 #include "libslic3r/Point.hpp"
 #include "libslic3r/Line.hpp"
diff --git a/src/libslic3r/Algorithm/LineSplit.hpp b/src/libslic3r/Algorithm/LineSplit.hpp
index e5577cdd7f..098ff72d09 100644
--- a/src/libslic3r/Algorithm/LineSplit.hpp
+++ b/src/libslic3r/Algorithm/LineSplit.hpp
@@ -2,6 +2,7 @@
 #define SRC_LIBSLIC3R_ALGORITHM_LINE_SPLIT_HPP_
 
 #include "ClipperZUtils.hpp"
+#include "libslic3r/libslic3r.h"
 #include "libslic3r/Point.hpp"
 #include <cstdint>
 #include <cstddef>
diff --git a/src/libslic3r/Arachne/utils/ExtrusionLine.cpp b/src/libslic3r/Arachne/utils/ExtrusionLine.cpp
index cb92fccab2..c1c29c50e9 100644
--- a/src/libslic3r/Arachne/utils/ExtrusionLine.cpp
+++ b/src/libslic3r/Arachne/utils/ExtrusionLine.cpp
@@ -10,6 +10,7 @@
 
 #include "ExtrusionLine.hpp"
 #include "../../VariableWidth.hpp"
+#include "libslic3r/ClipperZUtils.hpp"
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/Point.hpp"
 #include "libslic3r/Arachne/utils/ExtrusionJunction.hpp"
diff --git a/src/libslic3r/ClipperUtils.cpp b/src/libslic3r/ClipperUtils.cpp
index 88be185f8c..d80936515e 100644
--- a/src/libslic3r/ClipperUtils.cpp
+++ b/src/libslic3r/ClipperUtils.cpp
@@ -1,14 +1,29 @@
 #include <algorithm>
 #include <array>
+#include <cstddef>
+#include <cstdint>
+#include <cstdlib>
+#include <cassert>
+#include <cmath>
 #include <limits>
 #include <numeric>
 #include <unordered_map>
 
 #include "ClipperUtils.hpp"
+#include "BoundingBox.hpp"
+#include "ExPolygon.hpp"
 #include "Geometry.hpp"
+#include "Point.hpp"
+#include "Polygon.hpp"
+#include "Polyline.hpp"
+#include "Line.hpp"
 #include "ShortestPath.hpp"
+#include "libslic3r.h"
+#include "Surface.hpp"
 
 #include <clipper2/clipper.h>
+#include <utility>
+#include <vector>
 
 // #define CLIPPER_UTILS_DEBUG
 
diff --git a/src/libslic3r/ClipperZUtils.cpp b/src/libslic3r/ClipperZUtils.cpp
index f7a4b79b0d..a07f40dc4a 100644
--- a/src/libslic3r/ClipperZUtils.cpp
+++ b/src/libslic3r/ClipperZUtils.cpp
@@ -1,6 +1,8 @@
 #include "ClipperZUtils.hpp"
+#include "ClipperUtils.hpp"
 
 #include <clipper2/clipper2_z.hpp>
+#include <cstddef>
 
 namespace Slic3r {
 namespace ClipperZUtils {
diff --git a/src/libslic3r/ClipperZUtils.hpp b/src/libslic3r/ClipperZUtils.hpp
index 159a4e81b3..781357caa5 100644
--- a/src/libslic3r/ClipperZUtils.hpp
+++ b/src/libslic3r/ClipperZUtils.hpp
@@ -1,8 +1,13 @@
 #ifndef slic3r_ClipperZUtils_hpp_
 #define slic3r_ClipperZUtils_hpp_
 
+#include "libslic3r.h"
+#include <cstddef>
+#include <algorithm>
+#include <cassert>
 #include <functional>
 #include <numeric>
+#include <utility>
 #include <vector>
 
 #include <libslic3r/ClipperUtils.hpp>
diff --git a/src/libslic3r/ElephantFootCompensation.cpp b/src/libslic3r/ElephantFootCompensation.cpp
index aaf18608ee..40b856ee4b 100644
--- a/src/libslic3r/ElephantFootCompensation.cpp
+++ b/src/libslic3r/ElephantFootCompensation.cpp
@@ -1,3 +1,6 @@
+#include "Point.hpp"
+#include "BoundingBox.hpp"
+#include "Polygon.hpp"
 #include "libslic3r.h"
 #include "ClipperUtils.hpp"
 #include "EdgeGrid.hpp"
@@ -8,8 +11,14 @@
 #include "SVG.hpp"
 #include "Utils.hpp"
 
+#include <algorithm>
 #include <cmath>
 #include <cassert>
+#include <cstddef>
+#include <vector>
+#include <utility>
+#include <math.h>
+#include <limits>
 
 // #define CONTOUR_DISTANCE_DEBUG_SVG
 
diff --git a/src/libslic3r/Fill/FillBase.cpp b/src/libslic3r/Fill/FillBase.cpp
index 80c147f4a4..91a3bb42af 100644
--- a/src/libslic3r/Fill/FillBase.cpp
+++ b/src/libslic3r/Fill/FillBase.cpp
@@ -48,8 +48,6 @@
 #include "libslic3r/Line.hpp"
 #include "libslic3r/Polygon.hpp"
 #include "libslic3r/Utils.hpp"
-#include "clipper2/clipper.core.h"
-#include "clipper2/clipper.offset.h"
 // #define INFILL_DEBUG_OUTPUT
 
 namespace Slic3r {
diff --git a/src/libslic3r/Geometry.cpp b/src/libslic3r/Geometry.cpp
index 1c775be3a8..6c097428f4 100644
--- a/src/libslic3r/Geometry.cpp
+++ b/src/libslic3r/Geometry.cpp
@@ -1,16 +1,29 @@
+#include "Point.hpp"
+#include "Polygon.hpp"
+#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>
 #include <algorithm>
+#include <boost/algorithm/string/constants.hpp>
+#include <array>
 #include <cassert>
 #include <cmath>
+#include <cstddef>
+#include <cstdlib>
+#include <cstdint>
 #include <list>
 #include <map>
 #include <numeric>
 #include <set>
+#include <string>
 #include <utility>
 #include <stack>
 #include <vector>
diff --git a/src/libslic3r/PerimeterGenerator.cpp b/src/libslic3r/PerimeterGenerator.cpp
index 2f8e29c237..5b775f7e25 100644
--- a/src/libslic3r/PerimeterGenerator.cpp
+++ b/src/libslic3r/PerimeterGenerator.cpp
@@ -1,23 +1,41 @@
 #include "PerimeterGenerator.hpp"
 #include "AABBTreeLines.hpp"
+#include "Arachne/utils/ExtrusionLine.hpp"
+#include "Arachne/utils/ExtrusionJunction.hpp"
 #include "BridgeDetector.hpp"
 #include "ClipperUtils.hpp"
 #include "ClipperZUtils.hpp"
+#include "ExPolygon.hpp"
 #include "ExtrusionEntity.hpp"
 #include "ExtrusionEntityCollection.hpp"
 #include "Feature/FuzzySkin/FuzzySkin.hpp"
+#include "Polygon.hpp"
+#include "Polyline.hpp"
+#include "Point.hpp"
+#include "Flow.hpp"
 #include "PrintConfig.hpp"
 #include "ShortestPath.hpp"
+#include "Surface.hpp"
 #include "VariableWidth.hpp"
 #include "Arachne/WallToolPaths.hpp"
 #include "Geometry/ConvexHull.hpp"
 #include "ExPolygonCollection.hpp"
 #include "Geometry.hpp"
 #include "Line.hpp"
+#include <algorithm>
 #include <cmath>
 #include <cassert>
+#include <cstddef>
+#include <limits>
+#include <iterator>
+#include <map>
+#include <unordered_map>
+#include <tuple>
 #include <unordered_set>
 #include <thread>
+#include <vector>
+#include "libslic3r.h"
+#include <utility>
 #include "libslic3r/AABBTreeLines.hpp"
 #include "Print.hpp"
 static const int overhang_sampling_number = 6;
diff --git a/src/libslic3r/PrintObject.cpp b/src/libslic3r/PrintObject.cpp
index 26f4dc4b7d..d4201cf696 100644
--- a/src/libslic3r/PrintObject.cpp
+++ b/src/libslic3r/PrintObject.cpp
@@ -31,7 +31,6 @@
 #include "Fill/Fill.hpp"
 #include "Fill/FillLightning.hpp"
 #include "Format/STL.hpp"
-#include "clipper2/clipper.offset.h"
 #include "format.hpp"
 #include "AABBTreeIndirect.hpp"
 #include "AABBTreeLines.hpp"
diff --git a/src/libslic3r/Support/SupportCommon.cpp b/src/libslic3r/Support/SupportCommon.cpp
index d4495cf4a2..46ed7e968c 100644
--- a/src/libslic3r/Support/SupportCommon.cpp
+++ b/src/libslic3r/Support/SupportCommon.cpp
@@ -13,11 +13,27 @@
 #include <boost/log/trivial.hpp>
 
 #include <algorithm>
+#include <cstddef>
+#include <limits>
+#include <memory>
+#include <math.h>
+#include <initializer_list>
 #include <tbb/parallel_for.h>
+#include <utility>
+#include <vector>
+#include <unordered_map>
 
 #include "SupportCommon.hpp"
+#include "libslic3r/PrintConfig.hpp"
+#include "libslic3r/Polygon.hpp"
+#include "libslic3r/Slicing.hpp"
+#include "libslic3r/ExtrusionEntity.hpp"
+#include "libslic3r/Polyline.hpp"
 #include "SupportLayer.hpp"
 #include "SupportParameters.hpp"
+#include "libslic3r/libslic3r.h"
+#include "libslic3r/Surface.hpp"
+#include "libslic3r/Utils.hpp"
 
 // #define SLIC3R_DEBUG
 
diff --git a/src/libslic3r/Support/TreeSupport3D.cpp b/src/libslic3r/Support/TreeSupport3D.cpp
index 096bf91664..09f741ec25 100644
--- a/src/libslic3r/Support/TreeSupport3D.cpp
+++ b/src/libslic3r/Support/TreeSupport3D.cpp
@@ -12,6 +12,7 @@
 #include "BuildVolume.hpp"
 #include "ClipperUtils.hpp"
 #include "EdgeGrid.hpp"
+#include "libslic3r/Exception.hpp"
 #include "libslic3r/ExPolygon.hpp"
 #include "Fill/Fill.hpp"
 #include "libslic3r/Flow.hpp"