diff --git a/source/graphics/CinemaManager.cpp b/source/graphics/CinemaManager.cpp
index 04b0c9c2c9..ce26359bbb 100644
--- a/source/graphics/CinemaManager.cpp
+++ b/source/graphics/CinemaManager.cpp
@@ -23,6 +23,7 @@
 #include "graphics/CinemaManager.h"
 
 #include "graphics/Camera.h"
+#include "graphics/Color.h"
 #include "graphics/GameView.h"
 #include "lib/ogl.h"
 #include "maths/MathUtil.h"
@@ -41,6 +42,7 @@
 #include "simulation2/components/ICmpRangeManager.h"
 #include "simulation2/components/ICmpSelectable.h"
 #include "simulation2/components/ICmpTerritoryManager.h"
+#include "simulation2/helpers/CinemaPath.h"
 #include "simulation2/MessageTypes.h"
 #include "simulation2/system/ComponentManager.h"
 #include "simulation2/Simulation2.h"
diff --git a/source/graphics/CinemaManager.h b/source/graphics/CinemaManager.h
index 0835538dab..73812e98ce 100644
--- a/source/graphics/CinemaManager.h
+++ b/source/graphics/CinemaManager.h
@@ -18,11 +18,9 @@
 #ifndef INCLUDED_CINEMAMANAGER
 #define INCLUDED_CINEMAMANAGER
 
-#include "lib/input.h" // InReaction - can't forward-declare enum
-#include "graphics/Color.h"
-#include "ps/CStr.h"
-#include "simulation2/helpers/CinemaPath.h"
+class RNSpline;
 
+struct CColor;
 
 /**
  * Class for in game playing of cinematics. Should only be instantiated in CGameView.
diff --git a/source/graphics/Decal.h b/source/graphics/Decal.h
index 28411019c6..e82da4a4a0 100644
--- a/source/graphics/Decal.h
+++ b/source/graphics/Decal.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -20,7 +20,6 @@
 
 #include "graphics/Material.h"
 #include "graphics/ModelAbstract.h"
-#include "graphics/Texture.h"
 
 class CTerrain;
 
diff --git a/source/graphics/LOSTexture.h b/source/graphics/LOSTexture.h
index 16d65d3b9d..149739d5bc 100644
--- a/source/graphics/LOSTexture.h
+++ b/source/graphics/LOSTexture.h
@@ -17,10 +17,8 @@
 
 #include "lib/ogl.h"
 
-#include "maths/Matrix3D.h"
-
-#include "graphics/ShaderManager.h"
 #include "graphics/ShaderTechniquePtr.h"
+#include "maths/Matrix3D.h"
 
 class CLosQuerier;
 class CSimulation2;
diff --git a/source/graphics/MapGenerator.h b/source/graphics/MapGenerator.h
index c0cb5bf4fe..b3c9f9c5c3 100644
--- a/source/graphics/MapGenerator.h
+++ b/source/graphics/MapGenerator.h
@@ -18,13 +18,11 @@
 #ifndef INCLUDED_MAPGENERATOR
 #define INCLUDED_MAPGENERATOR
 
-#include "lib/posix/posix_pthread.h"
 #include "ps/FileIo.h"
 #include "ps/TemplateLoader.h"
 #include "scriptinterface/StructuredClone.h"
 
 #include <boost/random/linear_congruential.hpp>
-
 #include <mutex>
 #include <set>
 #include <string>
diff --git a/source/graphics/Model.h b/source/graphics/Model.h
index cc21fdff05..560ff0fafe 100644
--- a/source/graphics/Model.h
+++ b/source/graphics/Model.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -22,13 +22,12 @@
 #ifndef INCLUDED_MODEL
 #define INCLUDED_MODEL
 
-#include <vector>
-
-#include "graphics/Texture.h"
 #include "graphics/Material.h"
 #include "graphics/MeshManager.h"
 #include "graphics/ModelAbstract.h"
 
+#include <vector>
+
 struct SPropPoint;
 class CObjectEntry;
 class CSkeletonAnim;
diff --git a/source/graphics/ModelDef.h b/source/graphics/ModelDef.h
index 8ddfeeda4f..1144c0c7a6 100644
--- a/source/graphics/ModelDef.h
+++ b/source/graphics/ModelDef.h
@@ -22,13 +22,12 @@
 #ifndef INCLUDED_MODELDEF
 #define INCLUDED_MODELDEF
 
-#include "ps/CStr.h"
 #include "maths/BoundingBoxAligned.h"
 #include "maths/Matrix3D.h"
-#include "maths/Vector2D.h"
-#include "maths/Vector3D.h"
 #include "maths/Quaternion.h"
+#include "maths/Vector3D.h"
 #include "lib/file/vfs/vfs_path.h"
+#include "ps/CStr.h"
 #include "renderer/VertexArray.h"
 
 #include <cstring>
diff --git a/source/graphics/Overlay.h b/source/graphics/Overlay.h
index 73d294122e..7b25ff9dea 100644
--- a/source/graphics/Overlay.h
+++ b/source/graphics/Overlay.h
@@ -22,7 +22,6 @@
 #include "graphics/Texture.h"
 #include "maths/Vector2D.h"
 #include "maths/Vector3D.h"
-#include "maths/FixedVector3D.h"
 #include "ps/CStrIntern.h"
 
 #include <vector>
diff --git a/source/graphics/ParticleEmitter.h b/source/graphics/ParticleEmitter.h
index 918aab89b2..76b0bd0498 100644
--- a/source/graphics/ParticleEmitter.h
+++ b/source/graphics/ParticleEmitter.h
@@ -20,7 +20,6 @@
 
 #include "graphics/ModelAbstract.h"
 #include "graphics/ParticleEmitterType.h"
-#include "graphics/Texture.h"
 #include "maths/Quaternion.h"
 #include "renderer/VertexArray.h"
 
diff --git a/source/graphics/ShaderManager.cpp b/source/graphics/ShaderManager.cpp
index bd823ffc7b..1b50721671 100644
--- a/source/graphics/ShaderManager.cpp
+++ b/source/graphics/ShaderManager.cpp
@@ -29,13 +29,16 @@
 #include "ps/CStrIntern.h"
 #include "ps/Filesystem.h"
 #include "ps/Profile.h"
-#if USE_SHADER_XML_VALIDATION
-# include "ps/XML/RelaxNG.h"
-#endif
 #include "ps/XML/Xeromyces.h"
 #include "ps/XML/XMLWriter.h"
 #include "renderer/Renderer.h"
 
+#define USE_SHADER_XML_VALIDATION 1
+
+#if USE_SHADER_XML_VALIDATION
+# include "ps/XML/RelaxNG.h"
+#endif
+
 TIMER_ADD_CLIENT(tc_ShaderValidation);
 
 CShaderManager::CShaderManager()
diff --git a/source/graphics/ShaderManager.h b/source/graphics/ShaderManager.h
index 409a007936..22fc4ea72b 100644
--- a/source/graphics/ShaderManager.h
+++ b/source/graphics/ShaderManager.h
@@ -18,19 +18,13 @@
 #ifndef INCLUDED_SHADERMANAGER
 #define INCLUDED_SHADERMANAGER
 
-#define USE_SHADER_XML_VALIDATION 1
-
 #include "graphics/ShaderDefines.h"
 #include "graphics/ShaderProgram.h"
 #include "graphics/ShaderTechnique.h"
 
-#if USE_SHADER_XML_VALIDATION
-# include "ps/XML/RelaxNG.h"
-#endif
-
-#include <unordered_map>
 #include <memory>
 #include <set>
+#include <unordered_map>
 
 /**
  * Shader manager: loads and caches shader programs.
diff --git a/source/gui/CGUI.cpp b/source/gui/CGUI.cpp
index 7c98b64723..94fdfbf794 100644
--- a/source/gui/CGUI.cpp
+++ b/source/gui/CGUI.cpp
@@ -33,6 +33,7 @@
 #include "lib/sysdep/sysdep.h"
 #include "lib/timer.h"
 #include "lib/utf8.h"
+#include "maths/Size2D.h"
 #include "ps/CLogger.h"
 #include "ps/Filesystem.h"
 #include "ps/GameSetup/Config.h"
diff --git a/source/gui/CGUI.h b/source/gui/CGUI.h
index 79e573e334..a478b7a8b5 100644
--- a/source/gui/CGUI.h
+++ b/source/gui/CGUI.h
@@ -29,7 +29,6 @@
 #include "gui/SGUIStyle.h"
 #include "lib/input.h"
 #include "maths/Rect.h"
-#include "maths/Size2D.h"
 #include "maths/Vector2D.h"
 #include "ps/XML/Xeromyces.h"
 #include "scriptinterface/ScriptForward.h"
diff --git a/source/gui/ObjectTypes/CMiniMap.cpp b/source/gui/ObjectTypes/CMiniMap.cpp
index c246b1ceea..3191d42943 100644
--- a/source/gui/ObjectTypes/CMiniMap.cpp
+++ b/source/gui/ObjectTypes/CMiniMap.cpp
@@ -22,6 +22,7 @@
 #include "graphics/GameView.h"
 #include "graphics/LOSTexture.h"
 #include "graphics/MiniPatch.h"
+#include "graphics/ShaderManager.h"
 #include "graphics/Terrain.h"
 #include "graphics/TerrainTextureEntry.h"
 #include "graphics/TerrainTextureManager.h"
diff --git a/source/ps/CLogger.cpp b/source/ps/CLogger.cpp
index f7e6129c99..31bc8be5c1 100644
--- a/source/ps/CLogger.cpp
+++ b/source/ps/CLogger.cpp
@@ -22,6 +22,7 @@
 #include "graphics/FontMetrics.h"
 #include "graphics/ShaderManager.h"
 #include "graphics/TextRenderer.h"
+#include "lib/os_path.h"
 #include "lib/timer.h"
 #include "lib/utf8.h"
 #include "ps/CConsole.h"
diff --git a/source/ps/Game.h b/source/ps/Game.h
index 8316d9a41c..e850d6ecc6 100644
--- a/source/ps/Game.h
+++ b/source/ps/Game.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2020 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -18,20 +18,20 @@
 #ifndef INCLUDED_GAME
 #define INCLUDED_GAME
 
-#include <vector>
-
+#include "graphics/Color.h"
 #include "ps/CStr.h"
 #include "ps/Errors.h"
-#include "ps/Filesystem.h"
+#include "lib/os_path.h"
 #include "scriptinterface/ScriptTypes.h"
 #include "simulation2/helpers/Player.h"
 
-class CWorld;
-class CSimulation2;
+#include <vector>
+
 class CGameView;
+class CSimulation2;
 class CTurnManager;
+class CWorld;
 class IReplayLogger;
-struct CColor;
 
 /**
  * The container that holds the rules, resources and attributes of the game.
diff --git a/source/ps/scripting/JSInterface_Game.cpp b/source/ps/scripting/JSInterface_Game.cpp
index f2494fd9c1..48266d7878 100644
--- a/source/ps/scripting/JSInterface_Game.cpp
+++ b/source/ps/scripting/JSInterface_Game.cpp
@@ -23,6 +23,7 @@
 #include "network/NetClient.h"
 #include "network/NetServer.h"
 #include "ps/CLogger.h"
+#include "ps/Filesystem.h"
 #include "ps/Game.h"
 #include "ps/GameSetup/GameSetup.h"
 #include "ps/Replay.h"
diff --git a/source/renderer/DecalRData.h b/source/renderer/DecalRData.h
index 97608152d0..bdcb21241b 100644
--- a/source/renderer/DecalRData.h
+++ b/source/renderer/DecalRData.h
@@ -19,7 +19,6 @@
 #define INCLUDED_DECALRDATA
 
 #include "graphics/RenderableObject.h"
-#include "graphics/ShaderProgramPtr.h"
 #include "maths/Vector2D.h"
 #include "maths/Vector3D.h"
 #include "renderer/VertexBufferManager.h"
diff --git a/source/renderer/OverlayRenderer.cpp b/source/renderer/OverlayRenderer.cpp
index 13924c30ad..cee047a9ba 100644
--- a/source/renderer/OverlayRenderer.cpp
+++ b/source/renderer/OverlayRenderer.cpp
@@ -22,6 +22,7 @@
 #include "graphics/Camera.h"
 #include "graphics/LOSTexture.h"
 #include "graphics/Overlay.h"
+#include "graphics/ShaderManager.h"
 #include "graphics/Terrain.h"
 #include "graphics/TextureManager.h"
 #include "lib/hash.h"
diff --git a/source/renderer/OverlayRenderer.h b/source/renderer/OverlayRenderer.h
index 4327caf2b9..126287e9b4 100644
--- a/source/renderer/OverlayRenderer.h
+++ b/source/renderer/OverlayRenderer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Wildfire Games.
+/* Copyright (C) 2021 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 +18,7 @@
 #ifndef INCLUDED_OVERLAYRENDERER
 #define INCLUDED_OVERLAYRENDERER
 
-#include "graphics/ShaderManager.h"
+#include "graphics/ShaderProgramPtr.h"
 
 struct SOverlayLine;
 struct SOverlayTexturedLine;
diff --git a/source/renderer/PatchRData.h b/source/renderer/PatchRData.h
index e6c26ea547..42c5e9738a 100644
--- a/source/renderer/PatchRData.h
+++ b/source/renderer/PatchRData.h
@@ -20,7 +20,6 @@
 
 #include "graphics/Patch.h"
 #include "graphics/RenderableObject.h"
-#include "graphics/SColor.h"
 #include "graphics/ShaderProgramPtr.h"
 #include "maths/Vector2D.h"
 #include "maths/Vector3D.h"
diff --git a/source/renderer/TexturedLineRData.cpp b/source/renderer/TexturedLineRData.cpp
index 96592e5166..c64cb57088 100644
--- a/source/renderer/TexturedLineRData.cpp
+++ b/source/renderer/TexturedLineRData.cpp
@@ -19,6 +19,7 @@
 
 #include "TexturedLineRData.h"
 
+#include "graphics/ShaderProgram.h"
 #include "graphics/Terrain.h"
 #include "maths/Frustum.h"
 #include "maths/MathUtil.h"
diff --git a/source/simulation2/components/CCmpRallyPointRenderer.cpp b/source/simulation2/components/CCmpRallyPointRenderer.cpp
index 275ada1d96..08c449f7b9 100644
--- a/source/simulation2/components/CCmpRallyPointRenderer.cpp
+++ b/source/simulation2/components/CCmpRallyPointRenderer.cpp
@@ -18,6 +18,7 @@
 #include "precompiled.h"
 #include "CCmpRallyPointRenderer.h"
 
+#include "ps/Profile.h"
 #include "simulation2/components/ICmpRangeManager.h"
 #include "simulation2/helpers/Los.h"
 
diff --git a/source/simulation2/components/CCmpRallyPointRenderer.h b/source/simulation2/components/CCmpRallyPointRenderer.h
index 73c7b757ac..238568557c 100644
--- a/source/simulation2/components/CCmpRallyPointRenderer.h
+++ b/source/simulation2/components/CCmpRallyPointRenderer.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
@@ -19,8 +19,11 @@
 #define INCLUDED_CCMPRALLYPOINTRENDERER
 
 #include "ICmpRallyPointRenderer.h"
+
 #include "graphics/Overlay.h"
 #include "graphics/TextureManager.h"
+#include "ps/CLogger.h"
+#include "renderer/Renderer.h"
 #include "simulation2/MessageTypes.h"
 #include "simulation2/components/ICmpFootprint.h"
 #include "simulation2/components/ICmpObstructionManager.h"
@@ -36,10 +39,6 @@
 #include "simulation2/helpers/Geometry.h"
 #include "simulation2/system/Component.h"
 
-#include "ps/CLogger.h"
-#include "ps/Profile.h"
-#include "renderer/Renderer.h"
-
 struct SVisibilitySegment
 {
 	bool m_Visible;
diff --git a/source/simulation2/components/ICmpPathfinder.h b/source/simulation2/components/ICmpPathfinder.h
index f6a5cd0b9e..ea406f39b7 100644
--- a/source/simulation2/components/ICmpPathfinder.h
+++ b/source/simulation2/components/ICmpPathfinder.h
@@ -23,8 +23,6 @@
 #include "simulation2/components/ICmpObstruction.h"
 #include "simulation2/helpers/Pathfinding.h"
 
-#include "maths/FixedVector2D.h"
-
 #include <map>
 
 class IObstructionTestFilter;
diff --git a/source/tools/atlas/GameInterface/Handlers/GraphicsSetupHandlers.cpp b/source/tools/atlas/GameInterface/Handlers/GraphicsSetupHandlers.cpp
index d4a0170249..79aa03ae3f 100644
--- a/source/tools/atlas/GameInterface/Handlers/GraphicsSetupHandlers.cpp
+++ b/source/tools/atlas/GameInterface/Handlers/GraphicsSetupHandlers.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2021 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -32,6 +32,7 @@
 #include "lib/timer.h"
 #include "maths/MathUtil.h"
 #include "ps/CConsole.h"
+#include "ps/Filesystem.h"
 #include "ps/Profile.h"
 #include "ps/Profiler2.h"
 #include "ps/Game.h"