diff --git a/source/graphics/SColor.h b/source/graphics/SColor.h
index 42f8d400a6..65c2a2b039 100644
--- a/source/graphics/SColor.h
+++ b/source/graphics/SColor.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2009 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_SCOLOR
 #define INCLUDED_SCOLOR
 
+#include "lib/types.h"
+
 // SColor3ub: structure for packed RGB colors
 struct SColor3ub
 {
diff --git a/source/graphics/ShaderTechniquePtr.h b/source/graphics/ShaderTechniquePtr.h
index 7bee0f0cba..da2fb015bf 100644
--- a/source/graphics/ShaderTechniquePtr.h
+++ b/source/graphics/ShaderTechniquePtr.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
@@ -20,6 +20,8 @@
 #ifndef INCLUDED_SHADERTECHNIQUEPTR
 #define INCLUDED_SHADERTECHNIQUEPTR
 
+#include <memory>
+
 /*
  * Forward declaration, to reduce the number of header files that have to pull
  * in the whole of ShaderTechnique.h
diff --git a/source/graphics/Texture.h b/source/graphics/Texture.h
index 0e5f543f3a..0b8530506e 100644
--- a/source/graphics/Texture.h
+++ b/source/graphics/Texture.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 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_TEXTURE
 #define INCLUDED_TEXTURE
 
+#include <memory>
+
 // Forward-declare for CTextureManager handles
 class CTexture;
 typedef std::shared_ptr<CTexture> CTexturePtr;
diff --git a/source/gui/CGUI.h b/source/gui/CGUI.h
index 7d25bd1d1f..f9d1a8834c 100644
--- a/source/gui/CGUI.h
+++ b/source/gui/CGUI.h
@@ -24,36 +24,52 @@
 #define INCLUDED_CGUI
 
 #include "gui/GUITooltip.h"
-#include "gui/SettingTypes/CGUIColor.h"
 #include "gui/SGUIIcon.h"
 #include "gui/SGUIMessage.h"
 #include "gui/SGUIStyle.h"
+#include "gui/SettingTypes/CGUIColor.h"
+#include "lib/code_annotation.h"
+#include "lib/file/vfs/vfs_path.h"
 #include "lib/input.h"
+#include "lib/types.h"
 #include "maths/Rect.h"
-#include "maths/Size2D.h"
 #include "maths/Vector2D.h"
-#include "ps/XML/Xeromyces.h"
+#include "ps/CStr.h"
 #include "scriptinterface/ModuleLoader.h"
 #include "scriptinterface/StructuredClone.h"
-#include "scriptinterface/ScriptForward.h"
 
+#include <js/RootingAPI.h>
+#include <js/TypeDecls.h>
 #include <map>
 #include <memory>
 #include <optional>
+#include <string>
+#include <string_view>
 #include <unordered_map>
 #include <unordered_set>
+#include <utility>
 #include <vector>
 
-extern const double SELECT_DBLCLICK_RATE;
-
 class CCanvas2D;
-class CGUISpriteInstance;
 class CGUISprite;
+class CGUISpriteInstance;
+class CSize2D;
+class GUIProxyProps;
 class IGUIObject;
+class JSObject;
+class ScriptContext;
+class ScriptInterface;
+class ScriptRequest;
+class XMBData;
+class XMBElement;
+namespace JS { class HandleValueArray; }
+namespace JS { class Value; }
+namespace js { class BaseProxyHandler; }
+struct SDL_Event_;
 struct SGUIImageEffects;
 struct SGUIScrollBarStyle;
 
-class GUIProxyProps;
+extern const double SELECT_DBLCLICK_RATE;
 
 using map_pObjects = std::map<CStr, IGUIObject*>;
 
diff --git a/source/gui/CGUIScrollBarHorizontal.cpp b/source/gui/CGUIScrollBarHorizontal.cpp
index 9bf4989502..b7d6ccd7d9 100644
--- a/source/gui/CGUIScrollBarHorizontal.cpp
+++ b/source/gui/CGUIScrollBarHorizontal.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
@@ -20,6 +20,11 @@
 #include "CGUIScrollBarHorizontal.h"
 
 #include "gui/CGUI.h"
+#include "gui/CGUISprite.h"
+#include "gui/IGUIScrollBar.h"
+#include "gui/SGUIMessage.h"
+#include "maths/Rect.h"
+#include "maths/Vector2D.h"
 #include "ps/CLogger.h"
 
 CGUIScrollBarHorizontal::CGUIScrollBarHorizontal(CGUI& pGUI)
diff --git a/source/gui/CGUIScrollBarHorizontal.h b/source/gui/CGUIScrollBarHorizontal.h
index 0921b4a8fc..2f86798d74 100644
--- a/source/gui/CGUIScrollBarHorizontal.h
+++ b/source/gui/CGUIScrollBarHorizontal.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
@@ -26,6 +26,8 @@
 
 #include "IGUIScrollBar.h"
 
+class CGUI;
+
  /**
   * Horizontal implementation of IGUIScrollBar
   *
diff --git a/source/gui/CGUIScrollBarVertical.cpp b/source/gui/CGUIScrollBarVertical.cpp
index c562420f10..540db1e17e 100644
--- a/source/gui/CGUIScrollBarVertical.cpp
+++ b/source/gui/CGUIScrollBarVertical.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
@@ -20,6 +20,11 @@
 #include "CGUIScrollBarVertical.h"
 
 #include "gui/CGUI.h"
+#include "gui/CGUISprite.h"
+#include "gui/IGUIScrollBar.h"
+#include "gui/SGUIMessage.h"
+#include "maths/Rect.h"
+#include "maths/Vector2D.h"
 #include "ps/CLogger.h"
 
 CGUIScrollBarVertical::CGUIScrollBarVertical(CGUI& pGUI)
diff --git a/source/gui/CGUIScrollBarVertical.h b/source/gui/CGUIScrollBarVertical.h
index ad8647362e..0308d66964 100644
--- a/source/gui/CGUIScrollBarVertical.h
+++ b/source/gui/CGUIScrollBarVertical.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
@@ -26,6 +26,8 @@
 
 #include "IGUIScrollBar.h"
 
+class CGUI;
+
 /**
  * Vertical implementation of IGUIScrollBar
  *
diff --git a/source/gui/CGUISetting.h b/source/gui/CGUISetting.h
index 1296e2d345..1f6cfdf7d1 100644
--- a/source/gui/CGUISetting.h
+++ b/source/gui/CGUISetting.h
@@ -18,12 +18,14 @@
 #ifndef INCLUDED_CGUISETTINGS
 #define INCLUDED_CGUISETTINGS
 
+#include "lib/code_annotation.h"
 #include "ps/CStr.h"
-#include "scriptinterface/ScriptForward.h"
 
+#include <js/TypeDecls.h>
 #include <utility>
 
 class IGUIObject;
+class ScriptRequest;
 
 /**
  * This setting interface allows GUI objects to call setting function functions without having to know the setting type.
diff --git a/source/gui/CGUISprite.cpp b/source/gui/CGUISprite.cpp
index 0b326c7889..6a8b4a2374 100644
--- a/source/gui/CGUISprite.cpp
+++ b/source/gui/CGUISprite.cpp
@@ -19,6 +19,8 @@
 
 #include "CGUISprite.h"
 
+#include <utility>
+
 CGUISprite::~CGUISprite() = default;
 
 void CGUISprite::AddImage(std::unique_ptr<SGUIImage> image)
diff --git a/source/gui/CGUISprite.h b/source/gui/CGUISprite.h
index 6b551df478..d93566fcf6 100644
--- a/source/gui/CGUISprite.h
+++ b/source/gui/CGUISprite.h
@@ -24,9 +24,11 @@
 #define INCLUDED_CGUISPRITE
 
 #include "gui/GUIRenderer.h"
-#include "gui/SettingTypes/CGUISize.h"
 #include "gui/SettingTypes/CGUIColor.h"
+#include "gui/SettingTypes/CGUISize.h"
+#include "lib/code_annotation.h"
 #include "lib/file/vfs/vfs_path.h"
+#include "maths/Rect.h"
 #include "ps/CStr.h"
 #include "renderer/backend/Sampler.h"
 
@@ -35,6 +37,7 @@
 #include <vector>
 
 class CCanvas2D;
+class CGUI;
 
 struct SGUIImageEffects
 {
diff --git a/source/gui/CGUIText.cpp b/source/gui/CGUIText.cpp
index 777bfbbf1c..16426bc737 100644
--- a/source/gui/CGUIText.cpp
+++ b/source/gui/CGUIText.cpp
@@ -23,12 +23,15 @@
 #include "graphics/FontMetrics.h"
 #include "graphics/TextRenderer.h"
 #include "gui/CGUI.h"
-#include "gui/ObjectBases/IGUIObject.h"
+#include "gui/SGUIIcon.h"
 #include "gui/SettingTypes/CGUIString.h"
-#include "ps/CStrInternStatic.h"
+#include "gui/SettingTypes/EAlign.h"
+#include "lib/debug.h"
 
-#include <cmath>
+#include <algorithm>
+#include <iterator>
 #include <optional>
+#include <utility>
 
 extern int g_xres, g_yres;
 
diff --git a/source/gui/CGUIText.h b/source/gui/CGUIText.h
index 64f78ad08b..0f258cd25d 100644
--- a/source/gui/CGUIText.h
+++ b/source/gui/CGUIText.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2022 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
@@ -20,10 +20,11 @@
 
 #include "gui/CGUISprite.h"
 #include "gui/SettingTypes/CGUIColor.h"
-#include "gui/SettingTypes/EAlign.h"
+#include "lib/code_annotation.h"
 #include "maths/Rect.h"
 #include "maths/Size2D.h"
 #include "maths/Vector2D.h"
+#include "ps/CStr.h"
 #include "ps/CStrIntern.h"
 
 #include <array>
@@ -34,6 +35,7 @@ class CCanvas2D;
 class CGUI;
 class CGUIString;
 class IGUIObject;
+enum class EAlign;
 struct SGenerateTextImage;
 
 using SGenerateTextImages = std::array<std::vector<SGenerateTextImage>, 2>;
diff --git a/source/gui/GUIManager.cpp b/source/gui/GUIManager.cpp
index 85a9ebcd22..e30964e11e 100644
--- a/source/gui/GUIManager.cpp
+++ b/source/gui/GUIManager.cpp
@@ -28,6 +28,7 @@
 #include "ps/Profile.h"
 #include "ps/VideoMode.h"
 #include "ps/XML/Xeromyces.h"
+#include "ps/containers/StaticVector.h"
 #include "scriptinterface/FunctionWrapper.h"
 #include "scriptinterface/Object.h"
 #include "scriptinterface/Promises.h"
diff --git a/source/gui/GUIManager.h b/source/gui/GUIManager.h
index c6aef1de36..789eafe6ec 100644
--- a/source/gui/GUIManager.h
+++ b/source/gui/GUIManager.h
@@ -18,20 +18,32 @@
 #ifndef INCLUDED_GUIMANAGER
 #define INCLUDED_GUIMANAGER
 
+#include "lib/code_annotation.h"
 #include "lib/file/vfs/vfs_path.h"
 #include "lib/input.h"
-#include "ps/containers/StaticVector.h"
+#include "lib/path.h"
+#include "lib/status.h"
 #include "ps/CStr.h"
 #include "ps/TemplateLoader.h"
 #include "scriptinterface/StructuredClone.h"
 
+#include <cstddef>
 #include <deque>
+#include <js/TypeDecls.h>
+#include <memory>
 #include <optional>
 #include <string>
 #include <unordered_set>
 
 class CCanvas2D;
 class CGUI;
+class CParamNode;
+class ScriptContext;
+class ScriptInterface;
+namespace JS { class HandleValueArray; }
+namespace JS { class Value; }
+namespace PS { template <typename T, size_t N> class StaticVector; }
+struct SDL_Event_;
 
 /**
  * External interface to the GUI system.
diff --git a/source/gui/GUIObjectEventBroadcaster.h b/source/gui/GUIObjectEventBroadcaster.h
index 9ebf4024a3..34151c58e6 100644
--- a/source/gui/GUIObjectEventBroadcaster.h
+++ b/source/gui/GUIObjectEventBroadcaster.h
@@ -21,9 +21,14 @@
 #define GUIOBJECTEVENTBROADCASTER
 
 #include "gui/ObjectBases/IGUIObject.h"
-#include "gui/ObjectBases/IGUIPanel.h"
+#include "lib/alignment.h"
 #include "lib/allocators/DynamicArena.h"
 #include "lib/allocators/STLAllocators.h"
+#include "lib/types.h"
+
+#include <algorithm>
+#include <utility>
+#include <vector>
 
 namespace
 {
diff --git a/source/gui/GUIRenderer.h b/source/gui/GUIRenderer.h
index fa26b9f12e..e9fdb9d657 100644
--- a/source/gui/GUIRenderer.h
+++ b/source/gui/GUIRenderer.h
@@ -19,18 +19,17 @@
 #define INCLUDED_GUIRENDERER
 
 #include "graphics/Color.h"
-#include "graphics/ShaderTechniquePtr.h"
 #include "graphics/Texture.h"
 #include "maths/Rect.h"
-#include "ps/CStrForward.h"
-#include "ps/CStrIntern.h"
 
 #include <map>
+#include <memory>
 #include <vector>
 
 class CCanvas2D;
 class CGUI;
 class CGUISprite;
+class CStr8;
 struct CGUIColor;
 struct SGUIImage;
 
diff --git a/source/gui/GUIStringConversions.cpp b/source/gui/GUIStringConversions.cpp
index e6a8ead229..aab95be597 100644
--- a/source/gui/GUIStringConversions.cpp
+++ b/source/gui/GUIStringConversions.cpp
@@ -18,8 +18,9 @@
 #include "precompiled.h"
 
 #include "gui/CGUI.h"
-#include "gui/SettingTypes/EScrollOrientation.h"
 #include "gui/SettingTypes/CGUIString.h"
+#include "gui/SettingTypes/EAlign.h"
+#include "gui/SettingTypes/EScrollOrientation.h"
 #include "ps/CLogger.h"
 
 class CGUIList;
diff --git a/source/gui/GUITooltip.h b/source/gui/GUITooltip.h
index c1b585d8af..83ae65f691 100644
--- a/source/gui/GUITooltip.h
+++ b/source/gui/GUITooltip.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
@@ -21,6 +21,7 @@
 class IGUIObject;
 class CGUI;
 
+#include "lib/code_annotation.h"
 #include "maths/Vector2D.h"
 #include "ps/CStr.h"
 
diff --git a/source/gui/IGUIScrollBar.cpp b/source/gui/IGUIScrollBar.cpp
index fca34cf961..008fdbe08a 100644
--- a/source/gui/IGUIScrollBar.cpp
+++ b/source/gui/IGUIScrollBar.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
@@ -20,9 +20,10 @@
 #include "IGUIScrollBar.h"
 
 #include "gui/CGUI.h"
-#include "gui/SGUIMessage.h"
 #include "gui/ObjectBases/IGUIScrollBarOwner.h"
+#include "gui/SGUIMessage.h"
 #include "maths/MathUtil.h"
+#include "maths/Rect.h"
 
 IGUIScrollBar::IGUIScrollBar(CGUI& pGUI)
 	: m_pGUI(pGUI),
diff --git a/source/gui/IGUIScrollBar.h b/source/gui/IGUIScrollBar.h
index 419bb1a373..4a255e7917 100644
--- a/source/gui/IGUIScrollBar.h
+++ b/source/gui/IGUIScrollBar.h
@@ -25,11 +25,15 @@
 #define INCLUDED_IGUISCROLLBAR
 
 #include "gui/CGUISprite.h"
+#include "lib/code_annotation.h"
 #include "maths/Vector2D.h"
 #include "ps/CStr.h"
 
+#include <algorithm>
+
 class CCanvas2D;
 class CGUI;
+class CRect;
 class IGUIScrollBarOwner;
 struct SGUIMessage;
 
diff --git a/source/gui/ObjectBases/IGUIObject.h b/source/gui/ObjectBases/IGUIObject.h
index 2f7e877821..94a9832a32 100644
--- a/source/gui/ObjectBases/IGUIObject.h
+++ b/source/gui/ObjectBases/IGUIObject.h
@@ -33,11 +33,9 @@
 #include "lib/input.h"
 #include "maths/Rect.h"
 #include "ps/CStr.h"
-#include "ps/XMB/XMBData.h"
 
 #include <js/RootingAPI.h>
 #include <js/TypeDecls.h>
-#include <js/ValueArray.h>
 #include <map>
 #include <memory>
 #include <vector>
@@ -47,6 +45,9 @@ class CGUI;
 class IGUIProxyObject;
 class JSObject;
 class JSTracer;
+class XMBData;
+class XMBElement;
+namespace JS { class HandleValueArray; }
 struct SDL_Event_;
 
 #define GUI_OBJECT(obj) \
diff --git a/source/gui/ObjectBases/IGUIScrollBarOwner.cpp b/source/gui/ObjectBases/IGUIScrollBarOwner.cpp
index 0a08ac3aa8..e1bbf40721 100644
--- a/source/gui/ObjectBases/IGUIScrollBarOwner.cpp
+++ b/source/gui/ObjectBases/IGUIScrollBarOwner.cpp
@@ -22,6 +22,7 @@
 #include "gui/CGUI.h"
 #include "gui/IGUIScrollBar.h"
 #include "gui/ObjectBases/IGUIObject.h"
+#include "ps/CStr.h"
 
 #include <utility>
 
diff --git a/source/gui/ObjectBases/IGUIScrollBarOwner.h b/source/gui/ObjectBases/IGUIScrollBarOwner.h
index 8f6aa7b8ad..adfae306df 100644
--- a/source/gui/ObjectBases/IGUIScrollBarOwner.h
+++ b/source/gui/ObjectBases/IGUIScrollBarOwner.h
@@ -19,12 +19,12 @@
 #define INCLUDED_IGUISCROLLBAROWNER
 
 #include "lib/code_annotation.h"
-#include "ps/CStr.h"
 
 #include <memory>
 #include <vector>
 
 class CCanvas2D;
+class CStr8;
 class IGUIObject;
 class IGUIScrollBar;
 struct SGUIMessage;
diff --git a/source/gui/ObjectBases/IGUITextOwner.cpp b/source/gui/ObjectBases/IGUITextOwner.cpp
index 7d5e9f0d78..b5ca20b1d0 100644
--- a/source/gui/ObjectBases/IGUITextOwner.cpp
+++ b/source/gui/ObjectBases/IGUITextOwner.cpp
@@ -26,6 +26,7 @@
 #include "lib/debug.h"
 #include "maths/Size2D.h"
 #include "maths/Vector2D.h"
+#include "ps/CStr.h"
 
 #include <string>
 
diff --git a/source/gui/ObjectBases/IGUITextOwner.h b/source/gui/ObjectBases/IGUITextOwner.h
index 62ee8bc958..ad35aabd34 100644
--- a/source/gui/ObjectBases/IGUITextOwner.h
+++ b/source/gui/ObjectBases/IGUITextOwner.h
@@ -33,7 +33,6 @@ GUI Object Base - Text Owner
 #include "gui/CGUISetting.h"
 #include "lib/code_annotation.h"
 #include "maths/Rect.h"
-#include "ps/CStr.h"
 
 #include <cstddef>
 #include <vector>
@@ -41,6 +40,7 @@ GUI Object Base - Text Owner
 class CCanvas2D;
 class CGUIString;
 class CGUIText;
+class CStrW;
 class CVector2D;
 class IGUIObject;
 enum class EAlign;
diff --git a/source/gui/SGUIIcon.h b/source/gui/SGUIIcon.h
index 7a25eb4cc9..e3ff21437f 100644
--- a/source/gui/SGUIIcon.h
+++ b/source/gui/SGUIIcon.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
@@ -18,6 +18,7 @@
 #ifndef INCLUDED_SGUIICON
 #define INCLUDED_SGUIICON
 
+#include "lib/code_annotation.h"
 #include "maths/Size2D.h"
 #include "ps/CStr.h"
 
diff --git a/source/gui/SGUIMessage.h b/source/gui/SGUIMessage.h
index cd7e2d6917..92fdc2160f 100644
--- a/source/gui/SGUIMessage.h
+++ b/source/gui/SGUIMessage.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
@@ -18,6 +18,7 @@
 #ifndef INCLUDED_SGUIMESSAGE
 #define INCLUDED_SGUIMESSAGE
 
+#include "lib/code_annotation.h"
 #include "ps/CStr.h"
 
 /**
diff --git a/source/gui/SGUIStyle.h b/source/gui/SGUIStyle.h
index 42e3c6e9fb..44d5b92d0e 100644
--- a/source/gui/SGUIStyle.h
+++ b/source/gui/SGUIStyle.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 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_SGUISTYLE
 #define INCLUDED_SGUISTYLE
 
+#include "lib/code_annotation.h"
 #include "ps/CStr.h"
 
 #include <map>
diff --git a/source/gui/Scripting/GuiScriptConversions.cpp b/source/gui/Scripting/GuiScriptConversions.cpp
index 61e4baa544..6a221fbf56 100644
--- a/source/gui/Scripting/GuiScriptConversions.cpp
+++ b/source/gui/Scripting/GuiScriptConversions.cpp
@@ -18,16 +18,17 @@
 #include "precompiled.h"
 
 #include "gui/ObjectBases/IGUIObject.h"
-#include "gui/SettingTypes/EScrollOrientation.h"
+#include "gui/Scripting/JSInterface_GUIProxy.h"
 #include "gui/SettingTypes/CGUIColor.h"
 #include "gui/SettingTypes/CGUIList.h"
 #include "gui/SettingTypes/CGUISeries.h"
-#include "gui/Scripting/JSInterface_GUIProxy.h"
+#include "gui/SettingTypes/EAlign.h"
+#include "gui/SettingTypes/EScrollOrientation.h"
 #include "lib/external_libraries/libsdl.h"
 #include "maths/Size2D.h"
 #include "maths/Vector2D.h"
-#include "ps/Hotkey.h"
 #include "ps/CLogger.h"
+#include "ps/Hotkey.h"
 #include "scriptinterface/Object.h"
 #include "scriptinterface/ScriptConversions.h"
 
diff --git a/source/gui/SettingTypes/CGUIColor.h b/source/gui/SettingTypes/CGUIColor.h
index 87f371ef04..b61646b4e2 100644
--- a/source/gui/SettingTypes/CGUIColor.h
+++ b/source/gui/SettingTypes/CGUIColor.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
@@ -19,6 +19,7 @@
 #define INCLUDED_GUICOLOR
 
 #include "graphics/Color.h"
+#include "lib/code_annotation.h"
 #include "ps/CStrForward.h"
 
 class CGUI;
diff --git a/source/gui/SettingTypes/CGUISeries.h b/source/gui/SettingTypes/CGUISeries.h
index 259b607bfb..4a7b15572a 100644
--- a/source/gui/SettingTypes/CGUISeries.h
+++ b/source/gui/SettingTypes/CGUISeries.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 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 +19,7 @@
 #ifndef INCLUDED_CGUISERIES
 #define INCLUDED_CGUISERIES
 
+#include "lib/code_annotation.h"
 #include "maths/Vector2D.h"
 
 #include <vector>
diff --git a/source/gui/tests/test_CGUIText.h b/source/gui/tests/test_CGUIText.h
index 5887a706a9..9976c57d1d 100644
--- a/source/gui/tests/test_CGUIText.h
+++ b/source/gui/tests/test_CGUIText.h
@@ -22,12 +22,14 @@
 #include "gui/CGUI.h"
 #include "gui/CGUIText.h"
 #include "gui/SettingTypes/CGUIString.h"
+#include "gui/SettingTypes/EAlign.h"
 #include "i18n/L10n.h"
 #include "ps/CLogger.h"
 #include "ps/ConfigDB.h"
 #include "ps/Filesystem.h"
 #include "ps/ProfileViewer.h"
 #include "ps/VideoMode.h"
+#include "ps/XML/Xeromyces.h"
 #include "renderer/Renderer.h"
 #include "scriptinterface/ScriptInterface.h"
 
diff --git a/source/gui/tests/test_GUISetting.h b/source/gui/tests/test_GUISetting.h
index e3dd5ef435..d7ece91285 100644
--- a/source/gui/tests/test_GUISetting.h
+++ b/source/gui/tests/test_GUISetting.h
@@ -21,10 +21,10 @@
 #include "graphics/FontMetrics.h"
 #include "gui/CGUI.h"
 #include "gui/CGUISetting.h"
-#include "gui/Scripting/JSInterface_CGUISize.h"
-#include "gui/Scripting/JSInterface_GUIProxy.h"
 #include "gui/CGUIText.h"
 #include "gui/ObjectBases/IGUIObject.h"
+#include "gui/Scripting/JSInterface_CGUISize.h"
+#include "gui/Scripting/JSInterface_GUIProxy.h"
 #include "gui/SettingTypes/CGUISize.h"
 #include "gui/SettingTypes/CGUIString.h"
 #include "i18n/L10n.h"
@@ -33,6 +33,7 @@
 #include "ps/Filesystem.h"
 #include "ps/ProfileViewer.h"
 #include "ps/VideoMode.h"
+#include "ps/XML/Xeromyces.h"
 #include "renderer/Renderer.h"
 #include "scriptinterface/Object.h"
 #include "scriptinterface/ScriptContext.h"
diff --git a/source/lib/alignment.h b/source/lib/alignment.h
index 2f5b65c974..188ee234b1 100644
--- a/source/lib/alignment.h
+++ b/source/lib/alignment.h
@@ -23,9 +23,11 @@
 #ifndef INCLUDED_ALIGNMENT
 #define INCLUDED_ALIGNMENT
 
+#include "lib/code_annotation.h"
 #include "lib/sysdep/compiler.h"	// MSC_VERSION
 #include "lib/sysdep/arch.h"	// ARCH_AMD64
 
+#include <cstddef>
 #include <cstdint>
 
 template<typename T>
diff --git a/source/lib/lib.h b/source/lib/lib.h
index 4a7fd8ef4f..3bc200aaaa 100644
--- a/source/lib/lib.h
+++ b/source/lib/lib.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2019 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -60,6 +60,8 @@ scope
 #ifndef INCLUDED_LIB
 #define INCLUDED_LIB
 
+#include "lib/types.h"
+
 #include <cmath>	// fabsf
 #include <limits>	// numeric_limits
 #include <stdexcept>	// out_of_range
diff --git a/source/lib/path.h b/source/lib/path.h
index fe18579650..eae1353a9a 100644
--- a/source/lib/path.h
+++ b/source/lib/path.h
@@ -37,6 +37,8 @@
 #ifndef INCLUDED_PATH
 #define INCLUDED_PATH
 
+#include "lib/debug.h"
+#include "lib/status.h"
 #include "lib/sysdep/os.h"
 #include "lib/utf8.h"
 
diff --git a/source/lib/utf8.h b/source/lib/utf8.h
index 89eeff84fd..a2903d592e 100644
--- a/source/lib/utf8.h
+++ b/source/lib/utf8.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2022 Wildfire Games.
+/* Copyright (C) 2025 Wildfire Games.
  *
  * Permission is hereby granted, free of charge, to any person obtaining
  * a copy of this software and associated documentation files (the
@@ -23,6 +23,8 @@
 #ifndef INCLUDED_UTF8
 #define INCLUDED_UTF8
 
+#include "lib/status.h"
+
 #include <string>
 
 // note: error codes are returned via optional output parameter.
diff --git a/source/ps/CStr.h b/source/ps/CStr.h
index c451526596..b08abb2f29 100644
--- a/source/ps/CStr.h
+++ b/source/ps/CStr.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2022 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
@@ -50,6 +50,7 @@ enum PS_TRIM_MODE
 #define CSTR_H_A
 #endif
 
+#include "lib/types.h"
 #include "ps/CStrForward.h"
 
 #include <string>
diff --git a/source/ps/GameSetup/GameSetup.cpp b/source/ps/GameSetup/GameSetup.cpp
index 047ffa3416..50e08190fc 100644
--- a/source/ps/GameSetup/GameSetup.cpp
+++ b/source/ps/GameSetup/GameSetup.cpp
@@ -33,23 +33,23 @@
 #include "lib/input.h"
 #include "lib/timer.h"
 #include "lobby/IXmppClient.h"
-#include "network/NetServer.h"
 #include "network/NetClient.h"
 #include "network/NetMessage.h"
 #include "network/NetMessages.h"
+#include "network/NetServer.h"
 #include "network/scripting/JSInterface_Network.h"
 #include "ps/CConsole.h"
 #include "ps/CLogger.h"
 #include "ps/ConfigDB.h"
 #include "ps/Filesystem.h"
+#include "ps/GUID.h"
 #include "ps/Game.h"
 #include "ps/GameSetup/Atlas.h"
-#include "ps/GameSetup/Paths.h"
-#include "ps/GameSetup/Config.h"
 #include "ps/GameSetup/CmdLineArgs.h"
+#include "ps/GameSetup/Config.h"
 #include "ps/GameSetup/HWDetect.h"
+#include "ps/GameSetup/Paths.h"
 #include "ps/Globals.h"
-#include "ps/GUID.h"
 #include "ps/Hotkey.h"
 #include "ps/Joystick.h"
 #include "ps/Loader.h"
@@ -59,25 +59,26 @@
 #include "ps/ProfileViewer.h"
 #include "ps/Profiler2.h"
 #include "ps/Pyrogenesis.h"	// psSetLogDir
-#include "ps/scripting/JSInterface_Console.h"
-#include "ps/scripting/JSInterface_Game.h"
-#include "ps/scripting/JSInterface_Main.h"
-#include "ps/scripting/JSInterface_VFS.h"
 #include "ps/TouchInput.h"
 #include "ps/UserReport.h"
 #include "ps/Util.h"
 #include "ps/VideoMode.h"
 #include "ps/VisualReplay.h"
 #include "ps/World.h"
+#include "ps/XML/Xeromyces.h"
+#include "ps/scripting/JSInterface_Console.h"
+#include "ps/scripting/JSInterface_Game.h"
+#include "ps/scripting/JSInterface_Main.h"
+#include "ps/scripting/JSInterface_VFS.h"
 #include "renderer/Renderer.h"
 #include "renderer/SceneRenderer.h"
 #include "renderer/VertexBufferManager.h"
 #include "scriptinterface/FunctionWrapper.h"
 #include "scriptinterface/JSON.h"
-#include "scriptinterface/ScriptInterface.h"
-#include "scriptinterface/ScriptStats.h"
 #include "scriptinterface/ScriptContext.h"
 #include "scriptinterface/ScriptConversions.h"
+#include "scriptinterface/ScriptInterface.h"
+#include "scriptinterface/ScriptStats.h"
 #include "simulation2/Simulation2.h"
 #include "simulation2/scripting/JSInterface_Simulation.h"
 #include "soundmanager/scripting/JSInterface_Sound.h"