diff --git a/src/OrcaSlicer.cpp b/src/OrcaSlicer.cpp
index 1f85cf7358..15e7f85c46 100644
--- a/src/OrcaSlicer.cpp
+++ b/src/OrcaSlicer.cpp
@@ -4826,7 +4826,7 @@ int CLI::run(int argc, char **argv)
                     }
                 }
 
-                if (!arrange_cfg.is_seq_print && (assemble_plate.filaments_count > 1)||(enable_wrapping_detect && !current_wrapping_exclude_area.empty()))
+                if ((!arrange_cfg.is_seq_print && (assemble_plate.filaments_count > 1))||(enable_wrapping_detect && !current_wrapping_exclude_area.empty()))
                 {
                     //prepare the wipe tower
                     int plate_count = partplate_list.get_plate_count();
diff --git a/src/libslic3r/GCode/GCodeProcessor.cpp b/src/libslic3r/GCode/GCodeProcessor.cpp
index cd6c494f33..0b3db0323b 100644
--- a/src/libslic3r/GCode/GCodeProcessor.cpp
+++ b/src/libslic3r/GCode/GCodeProcessor.cpp
@@ -1468,9 +1468,11 @@ void GCodeProcessor::run_post_process()
 
     // Append a per-filament usage block at a filament change.
     auto handle_filament_change = [&](int filament_id, int cur_line_id, int nozzle_id) {
-        // skip filament changes emitted inside the machine start / end gcode
-        if (m_machine_start_gcode_end_line_id == (unsigned int) (-1) && (unsigned int) (cur_line_id) < m_machine_start_gcode_end_line_id ||
-            m_machine_end_gcode_start_line_id != (unsigned int) (-1) && (unsigned int) (cur_line_id) > m_machine_end_gcode_start_line_id)
+        // Skip filament changes emitted inside the machine start / end gcode. One forward pass assigns
+        // the tag ids and tests them in the same loop, so inside the start gcode the end tag is unseen
+        // and the id still holds the sentinel. That is why the first clause tests == and the second !=.
+        if ((m_machine_start_gcode_end_line_id == (unsigned int) (-1) && (unsigned int) (cur_line_id) < m_machine_start_gcode_end_line_id) ||
+            (m_machine_end_gcode_start_line_id != (unsigned int) (-1) && (unsigned int) (cur_line_id) > m_machine_end_gcode_start_line_id))
             return;
         if (!m_filament_blocks.empty())
             m_filament_blocks.back().upper_gcode_id = cur_line_id;
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 6921a72271..556faaa763 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -2191,7 +2191,7 @@ void GLCanvas3D::render(bool only_init)
 
 	// Negative coordinate means out of the window, likely because the window was deactivated.
 	// In that case the tooltip should be hidden.
-    if (m_mouse.position.x() >= 0. && m_mouse.position.y() >= 0. || has_mouse_capture()) { // ORCA continue to capture mouse pos mid drag
+    if ((m_mouse.position.x() >= 0. && m_mouse.position.y() >= 0.) || has_mouse_capture()) { // ORCA continue to capture mouse pos mid drag
         if (tooltip.empty())
             tooltip = m_layers_editing.get_tooltip(*this);
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 2d8816960b..109d7b3c10 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -3667,8 +3667,8 @@ void Sidebar::update_presets(Preset::Type preset_type)
                 // so extruders without an explicit sub-nozzle count never offer Hybrid. A nullable-int
                 // nil is INT_MAX (> 1) and would otherwise falsely pass the gate, so exclude it too.
                 if (boost::algorithm::contains(extruder_variants->values[index], type + " " + nozzle_volumes_def->enum_labels[i]) ||
-                    extruder_max_nozzle_count->get_at(index) > 1 && extruder_max_nozzle_count->get_at(index) != ConfigOptionIntsNullable::nil_value() &&
-                    nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]) == nvtHybrid) {
+                    (extruder_max_nozzle_count->get_at(index) > 1 && extruder_max_nozzle_count->get_at(index) != ConfigOptionIntsNullable::nil_value() &&
+                    nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]) == nvtHybrid)) {
                     if (nozzle_volumes_def->enum_keys_map->at(nozzle_volumes_def->enum_values[i]) == NozzleVolumeType::nvtHighFlow &&(diameter == "0.2" ||
                         is_skip_high_flow_printer(printer_model)))
                         continue;
diff --git a/src/slic3r/GUI/SelectMachine.cpp b/src/slic3r/GUI/SelectMachine.cpp
index 41ee523fbe..629aef7296 100644
--- a/src/slic3r/GUI/SelectMachine.cpp
+++ b/src/slic3r/GUI/SelectMachine.cpp
@@ -3073,7 +3073,7 @@ static bool _HasExt(const std::vector<FilamentInfo> &ams_mapping_result) {
     };
 
     for (const auto &info : ams_mapping_result) {
-        if (info.ams_id == VIRTUAL_AMS_MAIN_ID_STR || info.ams_id == VIRTUAL_AMS_DEPUTY_ID_STR && !info.ams_id.empty()) {
+        if (info.ams_id == VIRTUAL_AMS_MAIN_ID_STR || (info.ams_id == VIRTUAL_AMS_DEPUTY_ID_STR && !info.ams_id.empty())) {
             return true;
         }
     }
diff --git a/src/slic3r/GUI/UnsavedChangesDialog.cpp b/src/slic3r/GUI/UnsavedChangesDialog.cpp
index 5c69466cfa..0cb35fb139 100644
--- a/src/slic3r/GUI/UnsavedChangesDialog.cpp
+++ b/src/slic3r/GUI/UnsavedChangesDialog.cpp
@@ -1281,8 +1281,8 @@ static wxString get_string_value(std::string opt_key, const DynamicPrintConfig&
     }
     auto opt_vector = dynamic_cast<const ConfigOptionVectorBase *>(option);
 
-    if (option->is_scalar() && config.option(opt_key)->is_nil() ||
-        option->is_vector() && opt_vector && opt_idx >= 0 && opt_idx < opt_vector->size() && opt_vector->is_nil(opt_idx))
+    if ((option->is_scalar() && config.option(opt_key)->is_nil()) ||
+        (option->is_vector() && opt_vector && opt_idx >= 0 && opt_idx < opt_vector->size() && opt_vector->is_nil(opt_idx)))
         return _L("N/A");
 
     wxString out;