diff --git a/source/simulation2/components/tests/test_CinemaManager.h b/source/simulation2/components/tests/test_CinemaManager.h
index 7f65a77bc3..b2f7316166 100644
--- a/source/simulation2/components/tests/test_CinemaManager.h
+++ b/source/simulation2/components/tests/test_CinemaManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -15,9 +15,24 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
 
+#include "maths/Fixed.h"
+#include "maths/FixedVector3D.h"
+#include "maths/NUSpline.h"
+#include "ps/CStr.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
 #include "simulation2/components/ICmpCinemaManager.h"
+#include "simulation2/helpers/CinemaPath.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
+
+#include <cstddef>
+#include <memory>
+#include <string>
 
 class TestCmpCinemaManager : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/components/tests/test_CommandQueue.h b/source/simulation2/components/tests/test_CommandQueue.h
index 45538f34bc..2cc640b54d 100644
--- a/source/simulation2/components/tests/test_CommandQueue.h
+++ b/source/simulation2/components/tests/test_CommandQueue.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -15,9 +15,23 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
 
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptRequest.h"
 #include "simulation2/components/ICmpCommandQueue.h"
+#include "simulation2/helpers/SimulationCommand.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
+
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
+#include <memory>
+#include <string>
+#include <vector>
 
 class TestCmpCommandQueue : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/components/tests/test_HierPathfinder.h b/source/simulation2/components/tests/test_HierPathfinder.h
index 593d0d4071..cfccfddc7f 100644
--- a/source/simulation2/components/tests/test_HierPathfinder.h
+++ b/source/simulation2/components/tests/test_HierPathfinder.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -15,12 +15,23 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
+
+#include "lib/types.h"
+#include "maths/Fixed.h"
+#include "simulation2/helpers/Grid.h"
+#include "simulation2/helpers/PathGoal.h"
+#include "simulation2/helpers/Pathfinding.h"
+
+#include <cmath>
+#include <cstdio>
+#include <map>
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
 
 #define TEST
-
-#include "maths/Vector2D.h"
-#include "simulation2/helpers/Grid.h"
 #include "simulation2/helpers/HierarchicalPathfinder.h"
 
 class TestHierarchicalPathfinder : public CxxTest::TestSuite
diff --git a/source/simulation2/components/tests/test_ObstructionManager.h b/source/simulation2/components/tests/test_ObstructionManager.h
index 54251975ee..b19c10486b 100644
--- a/source/simulation2/components/tests/test_ObstructionManager.h
+++ b/source/simulation2/components/tests/test_ObstructionManager.h
@@ -15,12 +15,26 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
 
-#include "simulation2/components/ICmpObstructionManager.h"
+#include "maths/Fixed.h"
+#include "maths/FixedVector2D.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
 #include "simulation2/components/ICmpObstruction.h"
+#include "simulation2/components/ICmpObstructionManager.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
 
+#include <cmath>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
 #include <optional>
+#include <string>
+#include <vector>
 
 class MockObstruction : public ICmpObstruction
 {
diff --git a/source/simulation2/components/tests/test_Pathfinder.h b/source/simulation2/components/tests/test_Pathfinder.h
index 0b5db605dc..19f369a9dd 100644
--- a/source/simulation2/components/tests/test_Pathfinder.h
+++ b/source/simulation2/components/tests/test_Pathfinder.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -15,25 +15,44 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
-
-#include "simulation2/components/ICmpObstructionManager.h"
-#include "simulation2/components/ICmpPathfinder.h"
-#include "simulation2/helpers/Grid.h"
+#include "lib/self_test.h"
 
 #include "graphics/MapReader.h"
 #include "graphics/Terrain.h"
-#include "graphics/TerrainTextureManager.h"
+#include "lib/debug.h"
+#include "lib/file/file_system.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/os_path.h"
+#include "lib/path.h"
+#include "lib/posix/posix_types.h"
 #include "lib/timer.h"
-#include "lib/tex/tex.h"
+#include "lib/types.h"
+#include "maths/Fixed.h"
+#include "maths/FixedVector2D.h"
+#include "ps/Filesystem.h"
 #include "ps/Loader.h"
-#include "ps/Pyrogenesis.h"
-#include "scriptinterface/ScriptContext.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
 #include "simulation2/Simulation2.h"
+#include "simulation2/components/ICmpObstructionManager.h"
+#include "simulation2/components/ICmpPathfinder.h"
+#include "simulation2/helpers/Grid.h"
+#include "simulation2/helpers/PathGoal.h"
+#include "simulation2/helpers/Pathfinding.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/Entity.h"
 
+#include <cmath>
+#include <cstdio>
 #include <fstream>
+#include <js/CallArgs.h>
+#include <js/RootingAPI.h>
+#include <memory>
 #include <optional>
 #include <random>
+#include <string>
+#include <vector>
 
 class TestCmpPathfinder : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/components/tests/test_Position.h b/source/simulation2/components/tests/test_Position.h
index 7d5ae93101..3c5ba2b52a 100644
--- a/source/simulation2/components/tests/test_Position.h
+++ b/source/simulation2/components/tests/test_Position.h
@@ -15,11 +15,24 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
 
+#include "maths/Fixed.h"
+#include "maths/FixedVector3D.h"
 #include "maths/Matrix3D.h"
+#include "maths/Vector3D.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
 #include "simulation2/components/ICmpPosition.h"
 #include "simulation2/components/ICmpWaterManager.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
+
+#include <memory>
+#include <string>
 
 class MockWater : public ICmpWaterManager
 {
diff --git a/source/simulation2/components/tests/test_RangeManager.h b/source/simulation2/components/tests/test_RangeManager.h
index a707d9da6d..7fc89a1875 100644
--- a/source/simulation2/components/tests/test_RangeManager.h
+++ b/source/simulation2/components/tests/test_RangeManager.h
@@ -15,15 +15,34 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "maths/Matrix3D.h"
-#include "simulation2/system/ComponentTest.h"
-#include "simulation2/components/ICmpRangeManager.h"
-#include "simulation2/components/ICmpObstruction.h"
-#include "simulation2/components/ICmpPosition.h"
-#include "simulation2/components/ICmpVision.h"
+#include "lib/self_test.h"
 
-#include <random>
+#include "maths/Fixed.h"
+#include "maths/FixedVector2D.h"
+#include "maths/FixedVector3D.h"
+#include "maths/Matrix3D.h"
+#include "ps/CStr.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
+#include "simulation2/components/ICmpObstruction.h"
+#include "simulation2/components/ICmpObstructionManager.h"
+#include "simulation2/components/ICmpPosition.h"
+#include "simulation2/components/ICmpRangeManager.h"
+#include "simulation2/components/ICmpVision.h"
+#include "simulation2/helpers/Player.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <memory>
 #include <optional>
+#include <random>
+#include <string>
+#include <vector>
 
 class MockVisionRgm : public ICmpVision
 {
diff --git a/source/simulation2/components/tests/test_TerritoryManager.h b/source/simulation2/components/tests/test_TerritoryManager.h
index d50b14d42c..48ba8617f1 100644
--- a/source/simulation2/components/tests/test_TerritoryManager.h
+++ b/source/simulation2/components/tests/test_TerritoryManager.h
@@ -15,19 +15,45 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "simulation2/system/ComponentTest.h"
+#include "lib/self_test.h"
 
-#include "maths/Matrix3D.h"
-#include "ps/CStr.h"
-#include "graphics/Terrain.h"
 #include "graphics/TerritoryBoundary.h"
-#include "simulation2/helpers/Grid.h"
-#include "simulation2/components/ICmpTerritoryManager.h"
-#include "simulation2/components/ICmpPlayerManager.h"
-#include "simulation2/components/ICmpTerritoryInfluence.h"
+#include "lib/debug.h"
+#include "lib/file/file_system.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/path.h"
+#include "lib/types.h"
+#include "maths/Fixed.h"
+#include "maths/FixedVector2D.h"
+#include "maths/FixedVector3D.h"
+#include "maths/Matrix3D.h"
+#include "maths/Vector2D.h"
+#include "ps/CStr.h"
+#include "ps/Filesystem.h"
+#include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
+#include "simulation2/components/ICmpObstruction.h"
 #include "simulation2/components/ICmpOwnership.h"
+#include "simulation2/components/ICmpPathfinder.h"
+#include "simulation2/components/ICmpPlayerManager.h"
+#include "simulation2/components/ICmpPosition.h"
+#include "simulation2/components/ICmpTerritoryInfluence.h"
+#include "simulation2/components/ICmpTerritoryManager.h"
+#include "simulation2/helpers/Grid.h"
+#include "simulation2/helpers/Pathfinding.h"
+#include "simulation2/helpers/Player.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/ComponentTest.h"
+#include "simulation2/system/Entity.h"
 
+#include <cstddef>
+#include <cstdint>
+#include <memory>
 #include <optional>
+#include <string>
+#include <vector>
 
 class MockPathfinderTerrMan : public ICmpPathfinder
 {
diff --git a/source/simulation2/components/tests/test_scripts.h b/source/simulation2/components/tests/test_scripts.h
index 5e19aa23bc..1add87d35f 100644
--- a/source/simulation2/components/tests/test_scripts.h
+++ b/source/simulation2/components/tests/test_scripts.h
@@ -15,15 +15,33 @@
  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "lib/self_test.h"
+
+#include "lib/debug.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/file/vfs/vfs_path.h"
 #include "lib/file/vfs/vfs_util.h"
-#include "simulation2/system/ComponentTest.h"
-#include "simulation2/serialization/StdDeserializer.h"
-#include "simulation2/serialization/StdSerializer.h"
-
+#include "lib/path.h"
+#include "ps/CStr.h"
+#include "ps/Errors.h"
 #include "ps/Filesystem.h"
-
+#include "ps/XML/Xeromyces.h"
 #include "scriptinterface/FunctionWrapper.h"
 #include "scriptinterface/ScriptContext.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptRequest.h"
+#include "simulation2/serialization/StdDeserializer.h"
+#include "simulation2/serialization/StdSerializer.h"
+#include "simulation2/system/Component.h"
+
+#include <js/PropertyAndElement.h>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <vector>
 
 class TestComponentScripts : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/helpers/HierarchicalPathfinder.cpp b/source/simulation2/helpers/HierarchicalPathfinder.cpp
index ab1545cefb..e51d1a64b8 100644
--- a/source/simulation2/helpers/HierarchicalPathfinder.cpp
+++ b/source/simulation2/helpers/HierarchicalPathfinder.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,11 +19,24 @@
 
 #include "HierarchicalPathfinder.h"
 
+#include "graphics/Color.h"
 #include "graphics/Overlay.h"
+#include "lib/code_generation.h"
+#include "maths/Fixed.h"
+#include "maths/FixedVector2D.h"
 #include "ps/Profile.h"
+#include "ps/Profiler2.h"
 #include "renderer/Scene.h"
-
 #include "simulation2/helpers/Grid.h"
+#include "simulation2/helpers/PathGoal.h"
+#include "simulation2/helpers/Pathfinding.h"
+#include "simulation2/helpers/Position.h"
+#include "simulation2/helpers/Render.h"
+
+#include <algorithm>
+#include <cstring>
+
+class CSimContext;
 
 // Find the root ID of a region, used by InitRegions
 inline u16 RootID(u16 x, const std::vector<u16>& v)
diff --git a/source/simulation2/helpers/HierarchicalPathfinder.h b/source/simulation2/helpers/HierarchicalPathfinder.h
index d93af8e599..c0733d9c66 100644
--- a/source/simulation2/helpers/HierarchicalPathfinder.h
+++ b/source/simulation2/helpers/HierarchicalPathfinder.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -20,13 +20,25 @@
 
 #include "Pathfinding.h"
 
+#include "graphics/SColor.h"
+#include "lib/code_annotation.h"
+#include "lib/debug.h"
+#include "lib/types.h"
 #include "ps/CLogger.h"
 #include "renderer/TerrainOverlay.h"
-#include "Render.h"
-#include "graphics/SColor.h"
+#include "simulation2/helpers/Grid.h"
 
+#include <cstddef>
+#include <limits>
 #include <map>
 #include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+class CSimContext;
+class PathGoal;
+struct SOverlayLine;
 
 /**
  * Hierarchical pathfinder.
diff --git a/source/simulation2/helpers/Player.h b/source/simulation2/helpers/Player.h
index f55518613c..2c2c8e2653 100644
--- a/source/simulation2/helpers/Player.h
+++ b/source/simulation2/helpers/Player.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2010 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,6 +18,8 @@
 #ifndef INCLUDED_PLAYER
 #define INCLUDED_PLAYER
 
+#include <cstdint>
+
 /**
  * valid player IDs are non-negative (see ICmpOwnership)
  */
diff --git a/source/simulation2/scripting/EngineScriptConversions.cpp b/source/simulation2/scripting/EngineScriptConversions.cpp
index 47224766b1..183093851c 100644
--- a/source/simulation2/scripting/EngineScriptConversions.cpp
+++ b/source/simulation2/scripting/EngineScriptConversions.cpp
@@ -17,20 +17,37 @@
 
 #include "precompiled.h"
 
-#include "scriptinterface/Object.h"
-#include "scriptinterface/ScriptConversions.h"
-#include "scriptinterface/ScriptInterface.h"
-
 #include "graphics/Color.h"
+#include "lib/code_generation.h"
+#include "lib/types.h"
 #include "maths/Fixed.h"
 #include "maths/FixedVector2D.h"
 #include "maths/FixedVector3D.h"
-#include "maths/Rect.h"
+#include "maths/NUSpline.h"
 #include "ps/CLogger.h"
+#include "ps/CStr.h"
+#include "scriptinterface/Object.h"
+#include "scriptinterface/ScriptConversions.h"
+#include "scriptinterface/ScriptExceptions.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptRequest.h"
 #include "simulation2/helpers/CinemaPath.h"
 #include "simulation2/helpers/Grid.h"
-#include "simulation2/system/IComponent.h"
-#include "simulation2/system/ParamNode.h"
+#include "simulation2/system/Component.h"
+
+#include <cstring>
+#include <js/Array.h>
+#include <js/CallAndConstruct.h>
+#include <js/Conversions.h>
+#include <js/GCAPI.h>
+#include <js/PropertyAndElement.h>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
+#include <js/ValueArray.h>
+#include <js/experimental/TypedData.h>
+#include <string>
+#include <vector>
 
 #define FAIL(msg) STMT(LOGERROR(msg); return false)
 #define FAIL_VOID(msg) STMT(ScriptException::Raise(rq, msg); return)
diff --git a/source/simulation2/serialization/BinarySerializer.h b/source/simulation2/serialization/BinarySerializer.h
index ee31a6f72c..026aa89699 100644
--- a/source/simulation2/serialization/BinarySerializer.h
+++ b/source/simulation2/serialization/BinarySerializer.h
@@ -25,6 +25,7 @@
 #include "scriptinterface/ScriptExtraHeaders.h"
 #include "scriptinterface/ScriptForward.h"
 
+#include <memory>
 #include <ostream>
 #include <streambuf>
 
diff --git a/source/simulation2/serialization/IDeserializer.cpp b/source/simulation2/serialization/IDeserializer.cpp
index ab7e95405d..8bf69f6589 100644
--- a/source/simulation2/serialization/IDeserializer.cpp
+++ b/source/simulation2/serialization/IDeserializer.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2011 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -20,8 +20,10 @@
 #include "IDeserializer.h"
 
 #include "lib/byte_order.h"
+#include "lib/debug.h"
+#include "lib/status.h"
 #include "lib/utf8.h"
-#include "ps/CStr.h"
+#include "simulation2/system/Component.h"
 
 IDeserializer::~IDeserializer()
 {
diff --git a/source/simulation2/serialization/IDeserializer.h b/source/simulation2/serialization/IDeserializer.h
index a2a4d49967..416677d5f3 100644
--- a/source/simulation2/serialization/IDeserializer.h
+++ b/source/simulation2/serialization/IDeserializer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,10 +18,17 @@
 #ifndef INCLUDED_IDESERIALIZER
 #define INCLUDED_IDESERIALIZER
 
+#include "lib/types.h"
 #include "maths/Fixed.h"
 #include "ps/Errors.h"
 #include "scriptinterface/ScriptTypes.h"
 
+#include <cstddef>
+#include <cstdint>
+#include <iosfwd>
+#include <js/TypeDecls.h>
+#include <string>
+
 ERROR_GROUP(Deserialize);
 ERROR_TYPE(Deserialize, OutOfBounds);
 ERROR_TYPE(Deserialize, InvalidCharInString);
diff --git a/source/simulation2/serialization/ISerializer.cpp b/source/simulation2/serialization/ISerializer.cpp
index 92b9124e88..16d7c83a49 100644
--- a/source/simulation2/serialization/ISerializer.cpp
+++ b/source/simulation2/serialization/ISerializer.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2011 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,7 +19,11 @@
 
 #include "ISerializer.h"
 
+#include "lib/status.h"
 #include "lib/utf8.h"
+#include "simulation2/system/Component.h"
+
+#include <js/RootingAPI.h>
 
 ISerializer::~ISerializer()
 {
diff --git a/source/simulation2/serialization/ISerializer.h b/source/simulation2/serialization/ISerializer.h
index 18f3c0122f..295a09523d 100644
--- a/source/simulation2/serialization/ISerializer.h
+++ b/source/simulation2/serialization/ISerializer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,10 +18,17 @@
 #ifndef INCLUDED_ISERIALIZER
 #define INCLUDED_ISERIALIZER
 
+#include "lib/types.h"
 #include "maths/Fixed.h"
 #include "ps/Errors.h"
 #include "scriptinterface/ScriptTypes.h"
 
+#include <cstddef>
+#include <cstdint>
+#include <iosfwd>
+#include <js/TypeDecls.h>
+#include <string>
+
 ERROR_GROUP(Serialize);
 ERROR_TYPE(Serialize, OutOfBounds);
 ERROR_TYPE(Serialize, InvalidCharInString);
diff --git a/source/simulation2/serialization/StdDeserializer.cpp b/source/simulation2/serialization/StdDeserializer.cpp
index 46a372ef51..01d563fd39 100644
--- a/source/simulation2/serialization/StdDeserializer.cpp
+++ b/source/simulation2/serialization/StdDeserializer.cpp
@@ -19,18 +19,38 @@
 
 #include "StdDeserializer.h"
 
+#include "lib/alignment.h"
 #include "lib/byte_order.h"
+#include "lib/debug.h"
 #include "lib/utf8.h"
-#include "ps/CLogger.h"
 #include "ps/CStr.h"
 #include "scriptinterface/FunctionWrapper.h"
-#include "scriptinterface/Object.h"
-#include "scriptinterface/ScriptConversions.h"
-#include "scriptinterface/ScriptExtraHeaders.h" // For typed arrays and ArrayBuffer
+#include "scriptinterface/ScriptExtraHeaders.h"
 #include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptRequest.h"
 #include "simulation2/serialization/ISerializer.h"
 #include "simulation2/serialization/SerializedScriptTypes.h"
-#include "simulation2/serialization/StdSerializer.h" // for DEBUG_SERIALIZER_ANNOTATE
+#include "simulation2/serialization/StdSerializer.h"
+
+#include <cstdint>
+#include <cstdlib>
+#include <istream>
+#include <js/Array.h>
+#include <js/ArrayBuffer.h>
+#include <js/CallAndConstruct.h>
+#include <js/ComparisonOperators.h>
+#include <js/GCAPI.h>
+#include <js/MapAndSet.h>
+#include <js/PropertyAndElement.h>
+#include <js/RootingAPI.h>
+#include <js/String.h>
+#include <js/TracingAPI.h>
+#include <js/ValueArray.h>
+#include <js/experimental/TypedData.h>
+#include <jsapi.h>
+#include <jspubtd.h>
+
+class JSObject;
 
 CStdDeserializer::CStdDeserializer(const ScriptInterface& scriptInterface, std::istream& stream) :
 	m_ScriptInterface(scriptInterface), m_Stream(stream)
diff --git a/source/simulation2/serialization/StdSerializer.h b/source/simulation2/serialization/StdSerializer.h
index 33067245b4..e21fa54b7f 100644
--- a/source/simulation2/serialization/StdSerializer.h
+++ b/source/simulation2/serialization/StdSerializer.h
@@ -21,6 +21,7 @@
 #include "BinarySerializer.h"
 
 #include <cstring>
+#include <memory>
 
 #define DEBUG_SERIALIZER_ANNOTATE 0 // annotate the stream to help debugging if you're reading the output in a hex editor
 
diff --git a/source/simulation2/system/ComponentManager.cpp b/source/simulation2/system/ComponentManager.cpp
index 9795e59265..2da20f6d56 100644
--- a/source/simulation2/system/ComponentManager.cpp
+++ b/source/simulation2/system/ComponentManager.cpp
@@ -19,24 +19,38 @@
 
 #include "ComponentManager.h"
 
+#include "graphics/HeightMipmap.h"
 #include "lib/utf8.h"
-#include "ps/algorithm.h"
 #include "ps/CLogger.h"
+#include "ps/CStr.h"
+#include "ps/Errors.h"
 #include "ps/Filesystem.h"
-#include "ps/Profile.h"
+#include "ps/Profiler2.h"
+#include "ps/algorithm.h"
 #include "ps/scripting/JSInterface_VFS.h"
 #include "scriptinterface/FunctionWrapper.h"
 #include "scriptinterface/Object.h"
-#include "simulation2/components/ICmpTemplateManager.h"
+#include "scriptinterface/ScriptRequest.h"
 #include "simulation2/MessageTypes.h"
+#include "simulation2/components/ICmpTemplateManager.h"
+#include "simulation2/helpers/Player.h"
 #include "simulation2/system/DynamicSubscription.h"
-#include "simulation2/system/IComponent.h"
-#include "simulation2/system/ParamNode.h"
-#include "simulation2/system/SimContext.h"
+#include "simulation2/system/Message.h"
 
+#include <algorithm>
+#include <cstdint>
+#include <cstdlib>
+#include <fmt/format.h>
+#include <iterator>
+#include <js/GCAPI.h>
+#include <js/PropertyAndElement.h>
+#include <js/TracingAPI.h>
+#include <js/ValueArray.h>
 #include <stdexcept>
 #include <string_view>
 
+class ScriptContext;
+
 /**
  * Used for script-only message types.
  */
diff --git a/source/simulation2/system/ComponentManager.h b/source/simulation2/system/ComponentManager.h
index 10769e6149..b344c8d3aa 100644
--- a/source/simulation2/system/ComponentManager.h
+++ b/source/simulation2/system/ComponentManager.h
@@ -18,23 +18,30 @@
 #ifndef INCLUDED_COMPONENTMANAGER
 #define INCLUDED_COMPONENTMANAGER
 
-#include "ps/Filesystem.h"
+#include "lib/code_annotation.h"
+#include "lib/debug.h"
+#include "lib/types.h"
 #include "scriptinterface/ScriptInterface.h"
-#include "simulation2/helpers/Player.h"
-#include "simulation2/system/Components.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/DynamicSubscription.h"
 #include "simulation2/system/Entity.h"
-#include "simulation2/system/IComponent.h"
 
 #include <boost/random/linear_congruential.hpp>
+#include <iosfwd>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
 #include <map>
+#include <memory>
 #include <set>
+#include <string>
 #include <unordered_map>
+#include <utility>
+#include <vector>
 
-class IComponent;
-class CParamNode;
 class CMessage;
-class CSimContext;
-class CDynamicSubscription;
+class JSTracer;
+class ScriptContext;
 
 class CComponentManager
 {
diff --git a/source/simulation2/system/ComponentManagerSerialization.cpp b/source/simulation2/system/ComponentManagerSerialization.cpp
index a0972f2bac..686e8fb4e8 100644
--- a/source/simulation2/system/ComponentManagerSerialization.cpp
+++ b/source/simulation2/system/ComponentManagerSerialization.cpp
@@ -17,21 +17,28 @@
 
 #include "precompiled.h"
 
-#include "ComponentManager.h"
-#include "IComponent.h"
-#include "ParamNode.h"
-
-#include "simulation2/MessageTypes.h"
-
-#include "simulation2/serialization/DebugSerializer.h"
-#include "simulation2/serialization/HashSerializer.h"
-#include "simulation2/serialization/StdSerializer.h"
-#include "simulation2/serialization/StdDeserializer.h"
-
-#include "simulation2/components/ICmpTemplateManager.h"
-
+#include "lib/debug.h"
 #include "ps/CLogger.h"
 #include "ps/Profiler2.h"
+#include "simulation2/MessageTypes.h"
+#include "simulation2/components/ICmpTemplateManager.h"
+#include "simulation2/serialization/DebugSerializer.h"
+#include "simulation2/serialization/HashSerializer.h"
+#include "simulation2/serialization/StdDeserializer.h"
+#include "simulation2/serialization/StdSerializer.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/Entity.h"
+
+#include <algorithm>
+#include <boost/random/linear_congruential.hpp>
+#include <cstdint>
+#include <cstdio>
+#include <map>
+#include <set>
+#include <sstream>
+#include <string>
+#include <utility>
+#include <vector>
 
 std::string SerializeRNG(const boost::random::rand48& rng)
 {
diff --git a/source/simulation2/system/DynamicSubscription.cpp b/source/simulation2/system/DynamicSubscription.cpp
index a2e1a58e88..cf24c825da 100644
--- a/source/simulation2/system/DynamicSubscription.cpp
+++ b/source/simulation2/system/DynamicSubscription.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,6 +19,12 @@
 
 #include "DynamicSubscription.h"
 
+#include "lib/debug.h"
+
+#include <algorithm>
+#include <cstddef>
+#include <iterator>
+
 void CDynamicSubscription::Add(IComponent* cmp)
 {
 	m_Removed.erase(cmp);
diff --git a/source/simulation2/system/LocalTurnManager.cpp b/source/simulation2/system/LocalTurnManager.cpp
index d5ffb204af..2fb6b6d70f 100644
--- a/source/simulation2/system/LocalTurnManager.cpp
+++ b/source/simulation2/system/LocalTurnManager.cpp
@@ -19,6 +19,14 @@
 
 #include "LocalTurnManager.h"
 
+#include "lib/debug.h"
+#include "simulation2/system/TurnManager.h"
+
+#include <js/RootingAPI.h>
+
+class CSimulation2;
+class IReplayLogger;
+
 CLocalTurnManager::CLocalTurnManager(CSimulation2& simulation, IReplayLogger& replay)
 	: CTurnManager(simulation, DEFAULT_TURN_LENGTH, COMMAND_DELAY_SP, 0, replay)
 {
diff --git a/source/simulation2/system/LocalTurnManager.h b/source/simulation2/system/LocalTurnManager.h
index eb58417ca2..f6afe5d631 100644
--- a/source/simulation2/system/LocalTurnManager.h
+++ b/source/simulation2/system/LocalTurnManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,7 +18,14 @@
 #ifndef INCLUDED_LOCALTURNMANAGER
 #define INCLUDED_LOCALTURNMANAGER
 
-#include "TurnManager.h"
+#include "lib/types.h"
+#include "simulation2/helpers/Player.h"
+#include "simulation2/system/TurnManager.h"
+
+#include <js/TypeDecls.h>
+
+class CSimulation2;
+class IReplayLogger;
 
 /**
  * Implementation of CTurnManager for offline games.
diff --git a/source/simulation2/system/Message.h b/source/simulation2/system/Message.h
index 01d49a8254..8bf49caff5 100644
--- a/source/simulation2/system/Message.h
+++ b/source/simulation2/system/Message.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2023 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,6 +18,7 @@
 #ifndef INCLUDED_MESSAGE
 #define INCLUDED_MESSAGE
 
+#include "lib/code_annotation.h"
 #include "scriptinterface/ScriptTypes.h"
 
 class ScriptRequest;
diff --git a/source/simulation2/system/ParamNode.cpp b/source/simulation2/system/ParamNode.cpp
index 31daf05146..95b5fc5677 100644
--- a/source/simulation2/system/ParamNode.cpp
+++ b/source/simulation2/system/ParamNode.cpp
@@ -19,20 +19,36 @@
 
 #include "ParamNode.h"
 
+#include "lib/debug.h"
+#include "lib/path.h"
 #include "lib/utf8.h"
 #include "ps/CLogger.h"
 #include "ps/CStr.h"
 #include "ps/CStrIntern.h"
 #include "ps/Filesystem.h"
+#include "ps/XMB/XMBData.h"
 #include "ps/XML/Xeromyces.h"
 #include "scriptinterface/Object.h"
+#include "scriptinterface/ScriptInterface.h"
 #include "scriptinterface/ScriptRequest.h"
+#include "simulation2/system/Component.h"
 
+#include <algorithm>
 #include <boost/algorithm/string/classification.hpp>
+#include <boost/algorithm/string/constants.hpp>
 #include <boost/algorithm/string/join.hpp>
 #include <boost/algorithm/string/split.hpp>
+#include <cstdlib>
+#include <js/CharacterEncoding.h>
+#include <js/PropertyAndElement.h>
+#include <js/RootingAPI.h>
+#include <js/String.h>
+#include <js/Value.h>
+#include <jsapi.h>
 #include <sstream>
 #include <string_view>
+#include <utility>
+#include <vector>
 
 static CParamNode g_NullNode(false);
 
diff --git a/source/simulation2/system/ParamNode.h b/source/simulation2/system/ParamNode.h
index cb22fa33ad..b74c91aee0 100644
--- a/source/simulation2/system/ParamNode.h
+++ b/source/simulation2/system/ParamNode.h
@@ -19,18 +19,22 @@
 #define INCLUDED_PARAMNODE
 
 #include "lib/file/vfs/vfs_path.h"
+#include "lib/types.h"
 #include "maths/Fixed.h"
 #include "ps/Errors.h"
 #include "scriptinterface/ScriptTypes.h"
 
+#include <cstddef>
+#include <iosfwd>
+#include <js/TypeDecls.h>
 #include <map>
+#include <memory>
 #include <string>
 
-class XMBData;
-class XMBElement;
-
 class CStrIntern;
 class ScriptRequest;
+class XMBData;
+class XMBElement;
 
 /**
  * An entity initialisation parameter node.
diff --git a/source/simulation2/system/ReplayTurnManager.cpp b/source/simulation2/system/ReplayTurnManager.cpp
index 56c19a7804..eb246a1c6c 100644
--- a/source/simulation2/system/ReplayTurnManager.cpp
+++ b/source/simulation2/system/ReplayTurnManager.cpp
@@ -20,15 +20,26 @@
 #include "ReplayTurnManager.h"
 
 #include "gui/GUIManager.h"
+#include "lib/debug.h"
 #include "ps/CLogger.h"
 #include "ps/Util.h"
+#include "scriptinterface/JSON.h"
 #include "scriptinterface/ScriptConversions.h"
 #include "scriptinterface/ScriptRequest.h"
-#include "scriptinterface/JSON.h"
 #include "simulation2/Simulation2.h"
+#include "simulation2/system/LocalTurnManager.h"
 
+#include <js/GCVector.h>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
+#include <js/ValueArray.h>
+#include <tuple>
 #include <utility>
 
+class IReplayLogger;
+class ScriptInterface;
+
 const CStr CReplayTurnManager::EventNameReplayFinished = "ReplayFinished";
 const CStr CReplayTurnManager::EventNameReplayOutOfSync = "ReplayOutOfSync";
 
diff --git a/source/simulation2/system/ReplayTurnManager.h b/source/simulation2/system/ReplayTurnManager.h
index 67d52a84f8..880e6e8929 100644
--- a/source/simulation2/system/ReplayTurnManager.h
+++ b/source/simulation2/system/ReplayTurnManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2021 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,7 +18,18 @@
 #ifndef INCLUDED_REPLAYTURNMANAGER
 #define INCLUDED_REPLAYTURNMANAGER
 
-#include "LocalTurnManager.h"
+#include "lib/types.h"
+#include "ps/CStr.h"
+#include "simulation2/helpers/Player.h"
+#include "simulation2/system/LocalTurnManager.h"
+
+#include <map>
+#include <string>
+#include <utility>
+#include <vector>
+
+class CSimulation2;
+class IReplayLogger;
 
 /**
  * Implementation of CLocalTurnManager for replay games.
diff --git a/source/simulation2/system/SimContext.cpp b/source/simulation2/system/SimContext.cpp
index caefc4fb60..3c1eb8991a 100644
--- a/source/simulation2/system/SimContext.cpp
+++ b/source/simulation2/system/SimContext.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,9 +19,10 @@
 
 #include "SimContext.h"
 
-#include "ComponentManager.h"
-
 #include "ps/Game.h"
+#include "simulation2/system/Component.h"
+
+#include <cstddef>
 
 CSimContext::CSimContext(CTerrain* terrain /*= nullptr*/, CUnitManager* unitManager /*= nullptr*/) :
 	m_UnitManager{unitManager},
diff --git a/source/simulation2/system/SimContext.h b/source/simulation2/system/SimContext.h
index 137bacd9a5..2b90cd9864 100644
--- a/source/simulation2/system/SimContext.h
+++ b/source/simulation2/system/SimContext.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,7 +18,8 @@
 #ifndef INCLUDED_SIMCONTEXT
 #define INCLUDED_SIMCONTEXT
 
-#include "Entity.h"
+#include "lib/debug.h"
+#include "simulation2/system/Entity.h"
 
 class CComponentManager;
 class CUnitManager;
diff --git a/source/simulation2/system/TurnManager.cpp b/source/simulation2/system/TurnManager.cpp
index cc5fb32342..d8dc7df5fe 100644
--- a/source/simulation2/system/TurnManager.cpp
+++ b/source/simulation2/system/TurnManager.cpp
@@ -20,16 +20,24 @@
 #include "TurnManager.h"
 
 #include "gui/GUIManager.h"
+#include "lib/debug.h"
 #include "maths/MathUtil.h"
-#include "ps/Pyrogenesis.h"
+#include "ps/CLogger.h"
 #include "ps/Profile.h"
 #include "ps/Profiler2.h"
-#include "ps/CLogger.h"
 #include "ps/Replay.h"
-#include "ps/Util.h"
 #include "scriptinterface/Object.h"
+#include "scriptinterface/ScriptRequest.h"
+#include "scriptinterface/StructuredClone.h"
 #include "simulation2/Simulation2.h"
 
+#include <algorithm>
+#include <iterator>
+#include <js/ValueArray.h>
+#include <limits>
+#include <sstream>
+#include <utility>
+
 #if 0
 #define NETTURN_LOG(...) debug_printf(__VA_ARGS__)
 #else
diff --git a/source/simulation2/system/TurnManager.h b/source/simulation2/system/TurnManager.h
index c4f8ee9be4..b4a724dc99 100644
--- a/source/simulation2/system/TurnManager.h
+++ b/source/simulation2/system/TurnManager.h
@@ -19,12 +19,18 @@
 #define INCLUDED_TURNMANAGER
 
 #include "lib/code_annotation.h"
+#include "lib/types.h"
 #include "ps/CStr.h"
 #include "simulation2/helpers/SimulationCommand.h"
 
+#include <cstddef>
 #include <deque>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
 #include <list>
 #include <map>
+#include <string>
 #include <vector>
 
 class CSimulation2;
diff --git a/source/simulation2/tests/test_ComponentManager.h b/source/simulation2/tests/test_ComponentManager.h
index f1b77e8a11..c13381a22a 100644
--- a/source/simulation2/tests/test_ComponentManager.h
+++ b/source/simulation2/tests/test_ComponentManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -17,20 +17,27 @@
 
 #include "lib/self_test.h"
 
-#include "simulation2/system/ComponentManager.h"
-
-#include "simulation2/MessageTypes.h"
-#include "simulation2/system/ParamNode.h"
-#include "simulation2/system/SimContext.h"
-#include "simulation2/serialization/ISerializer.h"
-#include "simulation2/components/ICmpTest.h"
-#include "simulation2/components/ICmpTemplateManager.h"
-
+#include "lib/file/file_system.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/path.h"
+#include "lib/types.h"
+#include "maths/Fixed.h"
 #include "ps/CLogger.h"
+#include "ps/Errors.h"
 #include "ps/Filesystem.h"
 #include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
+#include "simulation2/components/ICmpTemplateManager.h"
+#include "simulation2/components/ICmpTest.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/Entity.h"
 
+#include <cstddef>
+#include <memory>
 #include <optional>
+#include <sstream>
+#include <string>
 
 #define TS_ASSERT_STREAM(stream, len, buffer) \
 	TS_ASSERT_EQUALS(stream.str().length(), (size_t)len); \
diff --git a/source/simulation2/tests/test_EntityMap.h b/source/simulation2/tests/test_EntityMap.h
index a933e9b32e..3159250236 100644
--- a/source/simulation2/tests/test_EntityMap.h
+++ b/source/simulation2/tests/test_EntityMap.h
@@ -16,15 +16,17 @@
  */
 
 #include "lib/self_test.h"
+
 #include "lib/timer.h"
-
-#include "simulation2/serialization/ISerializer.h"
-#include "simulation2/serialization/IDeserializer.h"
-
 #include "simulation2/system/EntityMap.h"
 
 #include <algorithm>
+#include <cstdio>
+#include <cstdlib>
+#include <new>
 #include <random>
+#include <utility>
+#include <vector>
 
 class TestEntityMap : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/tests/test_ParamNode.h b/source/simulation2/tests/test_ParamNode.h
index 84c1c4ef07..3441cf30eb 100644
--- a/source/simulation2/tests/test_ParamNode.h
+++ b/source/simulation2/tests/test_ParamNode.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -17,12 +17,13 @@
 
 #include "lib/self_test.h"
 
-#include "simulation2/system/ParamNode.h"
-
 #include "ps/CLogger.h"
+#include "ps/Errors.h"
 #include "ps/XML/Xeromyces.h"
+#include "simulation2/system/Component.h"
 
 #include <optional>
+#include <string>
 
 class TestParamNode : public CxxTest::TestSuite
 {
diff --git a/source/simulation2/tests/test_SerializeTemplates.h b/source/simulation2/tests/test_SerializeTemplates.h
index 9aac813be6..e34bb3c4d7 100644
--- a/source/simulation2/tests/test_SerializeTemplates.h
+++ b/source/simulation2/tests/test_SerializeTemplates.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -17,16 +17,20 @@
 
 #include "lib/self_test.h"
 
+#include "lib/types.h"
 #include "scriptinterface/ScriptInterface.h"
 #include "simulation2/helpers/Grid.h"
 #include "simulation2/serialization/DebugSerializer.h"
+#include "simulation2/serialization/SerializeTemplates.h"
+#include "simulation2/serialization/SerializedTypes.h"
 
+#include <array>
 #include <set>
 #include <sstream>
+#include <string>
+#include <utility>
 #include <vector>
 
-#include "simulation2/serialization/SerializedTypes.h"
-
 class TestSerializeTemplates : public CxxTest::TestSuite
 {
 public:
diff --git a/source/simulation2/tests/test_Serializer.h b/source/simulation2/tests/test_Serializer.h
index 381f687809..d3de02dd94 100644
--- a/source/simulation2/tests/test_Serializer.h
+++ b/source/simulation2/tests/test_Serializer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -17,31 +17,45 @@
 
 #include "lib/self_test.h"
 
-#include "simulation2/serialization/DebugSerializer.h"
-#include "simulation2/serialization/HashSerializer.h"
-#include "simulation2/serialization/StdSerializer.h"
-#include "simulation2/serialization/StdDeserializer.h"
-#include "scriptinterface/FunctionWrapper.h"
-#include "scriptinterface/ScriptContext.h"
-#include "scriptinterface/ScriptInterface.h"
-
 #include "graphics/MapReader.h"
 #include "graphics/Terrain.h"
-#include "graphics/TerrainTextureManager.h"
 #include "lib/config2.h"
+#include "lib/debug.h"
+#include "lib/file/file_system.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/path.h"
 #include "lib/timer.h"
+#include "lib/types.h"
+#include "maths/Fixed.h"
 #include "ps/CLogger.h"
 #include "ps/Filesystem.h"
 #include "ps/Loader.h"
 #include "ps/XML/Xeromyces.h"
+#include "scriptinterface/FunctionWrapper.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptRequest.h"
 #include "simulation2/Simulation2.h"
+#include "simulation2/serialization/DebugSerializer.h"
+#include "simulation2/serialization/HashSerializer.h"
+#include "simulation2/serialization/StdDeserializer.h"
+#include "simulation2/serialization/StdSerializer.h"
+#include "simulation2/system/Component.h"
+
+#include <cstdint>
+#include <cstdio>
+#include <iostream>
+#include <js/CallArgs.h>
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
+#include <js/Value.h>
+#include <memory>
+#include <sstream>
+#include <string>
 
 #if CONFIG2_VALGRIND
 # include "callgrind.h"
 #endif
 
-#include <iostream>
-
 #define TS_ASSERT_STREAM(stream, len, buffer) \
 	TS_ASSERT_EQUALS(stream.str().length(), (size_t)len); \
 	TS_ASSERT_SAME_DATA(stream.str().data(), buffer, len)
diff --git a/source/simulation2/tests/test_Simulation2.h b/source/simulation2/tests/test_Simulation2.h
index 470f42a910..d54c0c6c4a 100644
--- a/source/simulation2/tests/test_Simulation2.h
+++ b/source/simulation2/tests/test_Simulation2.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2024 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -17,15 +17,23 @@
 
 #include "lib/self_test.h"
 
-#include "scriptinterface/ScriptInterface.h"
-#include "simulation2/Simulation2.h"
-#include "simulation2/MessageTypes.h"
-#include "simulation2/components/ICmpTest.h"
-
 #include "graphics/Terrain.h"
-#include "ps/CLogger.h"
+#include "lib/file/file_system.h"
+#include "lib/file/vfs/vfs.h"
+#include "lib/path.h"
+#include "lib/types.h"
 #include "ps/Filesystem.h"
 #include "ps/XML/Xeromyces.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "simulation2/MessageTypes.h"
+#include "simulation2/Simulation2.h"
+#include "simulation2/components/ICmpTest.h"
+#include "simulation2/system/Component.h"
+#include "simulation2/system/Entity.h"
+
+#include <cstddef>
+#include <memory>
+#include <string>
 
 class TestSimulation2 : public CxxTest::TestSuite
 {