diff --git a/source/blender/animrig/ANIM_action.hh b/source/blender/animrig/ANIM_action.hh
index 81e548a5583..b4e096af60f 100644
--- a/source/blender/animrig/ANIM_action.hh
+++ b/source/blender/animrig/ANIM_action.hh
@@ -24,7 +24,6 @@
 
 #include <utility>
 
-struct AnimationEvalContext;
 struct FCurve;
 struct FCurve;
 struct ID;
diff --git a/source/blender/animrig/ANIM_keyframing.hh b/source/blender/animrig/ANIM_keyframing.hh
index 9fcd980766d..6b029fdbff0 100644
--- a/source/blender/animrig/ANIM_keyframing.hh
+++ b/source/blender/animrig/ANIM_keyframing.hh
@@ -25,10 +25,8 @@
 #include "RNA_types.hh"
 
 struct ID;
-struct ListBase;
 struct Main;
 struct Scene;
-struct ViewLayer;
 
 struct AnimationEvalContext;
 struct NlaKeyframingContext;
diff --git a/source/blender/blenkernel/BKE_armature.hh b/source/blender/blenkernel/BKE_armature.hh
index a7682b85f4d..0c3bf459a8e 100644
--- a/source/blender/blenkernel/BKE_armature.hh
+++ b/source/blender/blenkernel/BKE_armature.hh
@@ -17,7 +17,6 @@
 
 #include "DNA_armature_types.h"
 
-struct AnimationEvalContext;
 struct BMEditMesh;
 struct Bone;
 struct Depsgraph;
@@ -28,7 +27,6 @@ struct Mesh;
 struct Object;
 struct PoseTree;
 struct Scene;
-struct bAction;
 struct bArmature;
 struct bConstraint;
 struct bGPDstroke;
diff --git a/source/blender/blenkernel/BKE_asset_edit.hh b/source/blender/blenkernel/BKE_asset_edit.hh
index f60d0818674..691421a141c 100644
--- a/source/blender/blenkernel/BKE_asset_edit.hh
+++ b/source/blender/blenkernel/BKE_asset_edit.hh
@@ -32,7 +32,6 @@
 #include "DNA_ID_enums.h"
 
 struct bUserAssetLibrary;
-struct AssetMetaData;
 struct AssetWeakReference;
 struct ID;
 struct Main;
diff --git a/source/blender/blenkernel/BKE_blender_copybuffer.hh b/source/blender/blenkernel/BKE_blender_copybuffer.hh
index dd9c49e2ddf..d60e5628cfa 100644
--- a/source/blender/blenkernel/BKE_blender_copybuffer.hh
+++ b/source/blender/blenkernel/BKE_blender_copybuffer.hh
@@ -9,7 +9,6 @@
 
 #include "BLI_sys_types.h"
 
-struct ID;
 struct Main;
 struct ReportList;
 struct bContext;
diff --git a/source/blender/blenkernel/BKE_brush.hh b/source/blender/blenkernel/BKE_brush.hh
index 37f19bda2ee..7feab0275f5 100644
--- a/source/blender/blenkernel/BKE_brush.hh
+++ b/source/blender/blenkernel/BKE_brush.hh
@@ -23,7 +23,6 @@ struct ImagePool;
 struct Main;
 struct MTex;
 struct Scene;
-struct ToolSettings;
 struct UnifiedPaintSettings;
 
 // enum eCurveMappingPreset;
diff --git a/source/blender/blenkernel/BKE_gpencil_modifier_legacy.h b/source/blender/blenkernel/BKE_gpencil_modifier_legacy.h
index 77c0d3f6202..2d487d4a56e 100644
--- a/source/blender/blenkernel/BKE_gpencil_modifier_legacy.h
+++ b/source/blender/blenkernel/BKE_gpencil_modifier_legacy.h
@@ -13,22 +13,14 @@
 extern "C" {
 #endif
 
-struct ARegionType;
 struct BlendDataReader;
 struct BlendWriter;
-struct Depsgraph;
 struct GpencilModifierData;
 struct ID;
 struct ListBase;
-struct Main;
-struct ModifierUpdateDepsgraphContext;
 struct Object;
-struct Scene;
 /* NOTE: bake_modifier() called from UI:
  * needs to create new data-blocks, hence the need for this. */
-struct bGPDframe;
-struct bGPDlayer;
-struct bGPDstroke;
 
 typedef void (*GreasePencilIDWalkFunc)(void *user_data,
                                        struct Object *ob,
diff --git a/source/blender/blenkernel/BKE_grease_pencil_legacy_convert.hh b/source/blender/blenkernel/BKE_grease_pencil_legacy_convert.hh
index 4a8181c520a..162467f3373 100644
--- a/source/blender/blenkernel/BKE_grease_pencil_legacy_convert.hh
+++ b/source/blender/blenkernel/BKE_grease_pencil_legacy_convert.hh
@@ -8,15 +8,10 @@
  * \ingroup bke
  */
 
-struct bGPdata;
-struct bGPDframe;
 struct BlendfileLinkAppendContext;
 struct BlendFileReadReport;
 struct GreasePencil;
-struct GreasePencilDrawing;
-struct ListBase;
 struct Main;
-struct Object;
 struct LineartGpencilModifierData;
 struct GreasePencilLineartModifierData;
 
diff --git a/source/blender/blenkernel/BKE_mesh.hh b/source/blender/blenkernel/BKE_mesh.hh
index 73ce4536e81..0e01173d629 100644
--- a/source/blender/blenkernel/BKE_mesh.hh
+++ b/source/blender/blenkernel/BKE_mesh.hh
@@ -15,8 +15,6 @@
 #include "BKE_mesh.h"
 #include "BKE_mesh_types.hh"
 
-struct ModifierData;
-
 namespace blender::bke {
 
 enum class AttrDomain : int8_t;
diff --git a/source/blender/blenkernel/BKE_mesh_legacy_derived_mesh.hh b/source/blender/blenkernel/BKE_mesh_legacy_derived_mesh.hh
index eb3ffdfc2d7..5c54c27ce20 100644
--- a/source/blender/blenkernel/BKE_mesh_legacy_derived_mesh.hh
+++ b/source/blender/blenkernel/BKE_mesh_legacy_derived_mesh.hh
@@ -53,15 +53,10 @@
 
 #include "DNA_customdata_types.h"
 
-struct BMEditMesh;
 struct CCGElem;
 struct CCGKey;
 struct CustomData_MeshMasks;
-struct Depsgraph;
 struct Mesh;
-struct ModifierData;
-struct Object;
-struct Scene;
 
 enum DerivedMeshType {
   DM_TYPE_CDDM,
diff --git a/source/blender/blenkernel/BKE_object.hh b/source/blender/blenkernel/BKE_object.hh
index 653e9fdb517..178db52b99b 100644
--- a/source/blender/blenkernel/BKE_object.hh
+++ b/source/blender/blenkernel/BKE_object.hh
@@ -25,7 +25,6 @@ struct Base;
 struct BoundBox;
 struct Curve;
 struct Depsgraph;
-struct GpencilModifierData;
 struct HookGpencilModifierData;
 struct HookModifierData;
 struct ID;
diff --git a/source/blender/blenkernel/BKE_paint.hh b/source/blender/blenkernel/BKE_paint.hh
index 879423fbfbc..9965b2e84c4 100644
--- a/source/blender/blenkernel/BKE_paint.hh
+++ b/source/blender/blenkernel/BKE_paint.hh
@@ -30,6 +30,7 @@
 
 struct BMFace;
 struct BMLog;
+struct BMVert;
 struct BMesh;
 struct BlendDataReader;
 struct BlendWriter;
@@ -64,8 +65,6 @@ struct KeyBlock;
 struct Main;
 struct Mesh;
 struct MDeformVert;
-struct MLoopCol;
-struct MPropCol;
 struct MultiresModifierData;
 struct Object;
 struct Paint;
diff --git a/source/blender/blenkernel/BKE_pbvh.hh b/source/blender/blenkernel/BKE_pbvh.hh
index f50993be626..dcda3082356 100644
--- a/source/blender/blenkernel/BKE_pbvh.hh
+++ b/source/blender/blenkernel/BKE_pbvh.hh
@@ -11,8 +11,6 @@
 #include "BLI_utildefines.h"
 
 struct BMesh;
-struct BMVert;
-struct BMFace;
 
 namespace blender::bke::pbvh {
 
diff --git a/source/blender/blenkernel/BKE_pbvh_api.hh b/source/blender/blenkernel/BKE_pbvh_api.hh
index 52d36987536..2a35b86ed4c 100644
--- a/source/blender/blenkernel/BKE_pbvh_api.hh
+++ b/source/blender/blenkernel/BKE_pbvh_api.hh
@@ -39,7 +39,6 @@ struct BMLog;
 struct BMesh;
 struct CCGElem;
 struct CCGKey;
-struct CustomData;
 struct Depsgraph;
 struct IsectRayPrecalc;
 struct Mesh;
diff --git a/source/blender/blenkernel/BKE_preferences.h b/source/blender/blenkernel/BKE_preferences.h
index e719d83cdae..104d7ef64a5 100644
--- a/source/blender/blenkernel/BKE_preferences.h
+++ b/source/blender/blenkernel/BKE_preferences.h
@@ -16,7 +16,6 @@ extern "C" {
 #include "BLI_sys_types.h"
 
 struct BlendWriter;
-struct BlendReader;
 struct UserDef;
 struct bUserExtensionRepo;
 struct bUserAssetLibrary;
diff --git a/source/blender/blenkernel/BKE_scene.hh b/source/blender/blenkernel/BKE_scene.hh
index 2ba0672fe39..268e4319346 100644
--- a/source/blender/blenkernel/BKE_scene.hh
+++ b/source/blender/blenkernel/BKE_scene.hh
@@ -24,7 +24,6 @@ struct ToolSettings;
 struct TransformOrientation;
 struct TransformOrientationSlot;
 struct UnitSettings;
-struct View3DCursor;
 struct ViewLayer;
 
 enum eSceneCopyMethod {
diff --git a/source/blender/blenkernel/BKE_subsurf.hh b/source/blender/blenkernel/BKE_subsurf.hh
index 421ce2e8c49..570de20da9e 100644
--- a/source/blender/blenkernel/BKE_subsurf.hh
+++ b/source/blender/blenkernel/BKE_subsurf.hh
@@ -23,9 +23,10 @@ struct CCGSubSurf;
 struct CCGVert;
 struct DerivedMesh;
 struct Mesh;
-struct MeshElemMap;
 struct MultiresModifierData;
 struct Object;
+struct Scene;
+
 namespace blender::bke::pbvh {
 class Tree;
 }
diff --git a/source/blender/blenkernel/intern/mesh_legacy_derived_mesh.cc b/source/blender/blenkernel/intern/mesh_legacy_derived_mesh.cc
index 43af204b019..8af6dbe0d42 100644
--- a/source/blender/blenkernel/intern/mesh_legacy_derived_mesh.cc
+++ b/source/blender/blenkernel/intern/mesh_legacy_derived_mesh.cc
@@ -10,8 +10,6 @@
 #include "BKE_customdata.hh"
 #include "BKE_mesh_legacy_derived_mesh.hh"
 
-struct MeshElemMap;
-
 /* -------------------------------------------------------------------- */
 
 static float *dm_getVertArray(DerivedMesh *dm)
diff --git a/source/blender/blenlib/BLI_task.h b/source/blender/blenlib/BLI_task.h
index fc162b3d1bd..39e3e755066 100644
--- a/source/blender/blenlib/BLI_task.h
+++ b/source/blender/blenlib/BLI_task.h
@@ -8,8 +8,6 @@
 
 #include <string.h> /* for memset() */
 
-struct ListBase;
-
 /** \file
  * \ingroup bli
  */
diff --git a/source/blender/blenloader/BLO_read_write.hh b/source/blender/blenloader/BLO_read_write.hh
index 56d6d5443fb..83b44975e9d 100644
--- a/source/blender/blenloader/BLO_read_write.hh
+++ b/source/blender/blenloader/BLO_read_write.hh
@@ -45,7 +45,6 @@ struct BlendDataReader;
 struct BlendFileReadReport;
 struct BlendLibReader;
 struct BlendWriter;
-struct LibraryIDLinkCallbackData;
 struct Main;
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/blenloader/BLO_undofile.hh b/source/blender/blenloader/BLO_undofile.hh
index 83ee072c456..ed0a7a9ee94 100644
--- a/source/blender/blenloader/BLO_undofile.hh
+++ b/source/blender/blenloader/BLO_undofile.hh
@@ -16,7 +16,6 @@
 namespace blender {
 class ImplicitSharingInfo;
 }
-struct GHash;
 struct Main;
 struct Scene;
 
diff --git a/source/blender/blenloader/intern/readfile.hh b/source/blender/blenloader/intern/readfile.hh
index 2dc895e40c6..3f6727cd4ef 100644
--- a/source/blender/blenloader/intern/readfile.hh
+++ b/source/blender/blenloader/intern/readfile.hh
@@ -35,7 +35,6 @@ struct Main;
 struct MemFile;
 struct Object;
 struct OldNewMap;
-struct ReportList;
 struct UserDef;
 
 enum eFileDataFlag {
diff --git a/source/blender/compositor/operations/COM_FileOutputOperation.h b/source/blender/compositor/operations/COM_FileOutputOperation.h
index 68660d29c45..ad042baefcd 100644
--- a/source/blender/compositor/operations/COM_FileOutputOperation.h
+++ b/source/blender/compositor/operations/COM_FileOutputOperation.h
@@ -11,8 +11,6 @@
 #include "COM_CompositorContext.h"
 #include "COM_NodeOperation.h"
 
-struct StampData;
-
 namespace blender::realtime_compositor {
 class FileOutput;
 }
diff --git a/source/blender/draw/DRW_engine.hh b/source/blender/draw/DRW_engine.hh
index 177756152a6..3fb2518b2d7 100644
--- a/source/blender/draw/DRW_engine.hh
+++ b/source/blender/draw/DRW_engine.hh
@@ -22,8 +22,6 @@ struct GHash;
 struct GPUMaterial;
 struct GPUOffScreen;
 struct GPUVertFormat;
-struct CustomDataLayer;
-struct CustomData;
 struct GPUViewport;
 struct ID;
 struct Main;
diff --git a/source/blender/draw/DRW_pbvh.hh b/source/blender/draw/DRW_pbvh.hh
index c7bbb749c32..c717405c34a 100644
--- a/source/blender/draw/DRW_pbvh.hh
+++ b/source/blender/draw/DRW_pbvh.hh
@@ -24,13 +24,7 @@ class Batch;
 class IndexBuf;
 class VertBuf;
 }  // namespace blender::gpu
-struct Mesh;
-struct CustomData;
 struct Object;
-struct SubdivCCG;
-struct BMesh;
-struct BMFace;
-struct RegionView3D;
 namespace blender::bke {
 enum class AttrDomain : int8_t;
 namespace pbvh {
diff --git a/source/blender/draw/engines/eevee_next/eevee_lightprobe_planar.hh b/source/blender/draw/engines/eevee_next/eevee_lightprobe_planar.hh
index e467a39ef2e..d8a5451213a 100644
--- a/source/blender/draw/engines/eevee_next/eevee_lightprobe_planar.hh
+++ b/source/blender/draw/engines/eevee_next/eevee_lightprobe_planar.hh
@@ -13,14 +13,12 @@
 #include "BKE_cryptomatte.hh"
 
 extern "C" {
-struct Material;
 }
 
 namespace blender::eevee {
 
 class Instance;
 class HiZBuffer;
-struct ObjectHandle;
 
 /* -------------------------------------------------------------------- */
 /** \name Planar Probe Module
diff --git a/source/blender/draw/engines/eevee_next/eevee_lightprobe_sphere.hh b/source/blender/draw/engines/eevee_next/eevee_lightprobe_sphere.hh
index b1ab74831d3..c34865d5d31 100644
--- a/source/blender/draw/engines/eevee_next/eevee_lightprobe_sphere.hh
+++ b/source/blender/draw/engines/eevee_next/eevee_lightprobe_sphere.hh
@@ -14,14 +14,11 @@
 #include "BKE_cryptomatte.hh"
 
 extern "C" {
-struct Material;
 }
 
 namespace blender::eevee {
 
 class Instance;
-struct ObjectHandle;
-struct WorldHandle;
 class CaptureView;
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/draw/engines/overlay/overlay_private.hh b/source/blender/draw/engines/overlay/overlay_private.hh
index 99b63dbd5cd..c97abd147b3 100644
--- a/source/blender/draw/engines/overlay/overlay_private.hh
+++ b/source/blender/draw/engines/overlay/overlay_private.hh
@@ -31,7 +31,6 @@
 #include "DNA_mask_types.h"
 #include "DNA_space_types.h"
 /* Forward declarations */
-struct ImBuf;
 
 struct OVERLAY_FramebufferList {
   GPUFrameBuffer *overlay_default_fb;
diff --git a/source/blender/draw/intern/draw_common_c.hh b/source/blender/draw/intern/draw_common_c.hh
index 836a23e7264..1c6f0e70f30 100644
--- a/source/blender/draw/intern/draw_common_c.hh
+++ b/source/blender/draw/intern/draw_common_c.hh
@@ -14,7 +14,9 @@ struct DRWShadingGroup;
 struct DRWView;
 struct FluidModifierData;
 struct GPUMaterial;
+struct GPUTexture;
 struct GPUUniformBuf;
+
 namespace blender::gpu {
 class VertBuf;
 }
diff --git a/source/blender/draw/intern/draw_debug_c.hh b/source/blender/draw/intern/draw_debug_c.hh
index 6dcd84a1dd9..f6fe41ce844 100644
--- a/source/blender/draw/intern/draw_debug_c.hh
+++ b/source/blender/draw/intern/draw_debug_c.hh
@@ -11,8 +11,6 @@
 
 #pragma once
 
-struct DRWDebugModule;
-
 struct BoundBox;
 
 void DRW_debug_modelmat_reset();
diff --git a/source/blender/draw/intern/draw_manager_c.hh b/source/blender/draw/intern/draw_manager_c.hh
index f5394ce91e0..296312840a6 100644
--- a/source/blender/draw/intern/draw_manager_c.hh
+++ b/source/blender/draw/intern/draw_manager_c.hh
@@ -30,6 +30,7 @@
 #include "draw_instance_data.hh"
 #include "draw_shader_shared.hh"
 
+struct DRWDebugModule;
 struct DRWTexturePool;
 struct DRWUniformChunk;
 struct DupliObject;
diff --git a/source/blender/editors/asset/ED_asset_catalog.hh b/source/blender/editors/asset/ED_asset_catalog.hh
index 97eb7dc6a5f..1741c54cdab 100644
--- a/source/blender/editors/asset/ED_asset_catalog.hh
+++ b/source/blender/editors/asset/ED_asset_catalog.hh
@@ -23,8 +23,6 @@
 
 #include "BLI_string_ref.hh"
 
-struct bScreen;
-
 namespace blender::ed::asset {
 
 void catalogs_save_from_main_path(asset_system::AssetLibrary *library, const Main *bmain);
diff --git a/source/blender/editors/asset/ED_asset_shelf.hh b/source/blender/editors/asset/ED_asset_shelf.hh
index 5c99f6f979a..10063fc0c9e 100644
--- a/source/blender/editors/asset/ED_asset_shelf.hh
+++ b/source/blender/editors/asset/ED_asset_shelf.hh
@@ -20,8 +20,6 @@ struct bContextDataResult;
 struct BlendDataReader;
 struct BlendWriter;
 struct Main;
-struct SpaceType;
-struct uiBlock;
 struct RegionPollParams;
 struct wmRegionMessageSubscribeParams;
 struct wmWindowManager;
diff --git a/source/blender/editors/asset/intern/asset_shelf.hh b/source/blender/editors/asset/intern/asset_shelf.hh
index 854dd1af668..402d6bdd517 100644
--- a/source/blender/editors/asset/intern/asset_shelf.hh
+++ b/source/blender/editors/asset/intern/asset_shelf.hh
@@ -20,7 +20,6 @@ struct bContext;
 struct BlendDataReader;
 struct BlendWriter;
 struct RegionAssetShelf;
-struct SpaceType;
 struct uiLayout;
 
 namespace blender::asset_system {
diff --git a/source/blender/editors/include/ED_asset_menu_utils.hh b/source/blender/editors/include/ED_asset_menu_utils.hh
index 93355d5d93e..bd32906af1b 100644
--- a/source/blender/editors/include/ED_asset_menu_utils.hh
+++ b/source/blender/editors/include/ED_asset_menu_utils.hh
@@ -14,7 +14,6 @@
 
 #include "RNA_types.hh"
 
-struct bScreen;
 struct uiLayout;
 
 namespace blender::asset_system {
diff --git a/source/blender/editors/include/ED_curves.hh b/source/blender/editors/include/ED_curves.hh
index 3e6dba4c8ff..1b40d90f193 100644
--- a/source/blender/editors/include/ED_curves.hh
+++ b/source/blender/editors/include/ED_curves.hh
@@ -20,7 +20,6 @@
 struct bContext;
 struct Curves;
 struct UndoType;
-struct SelectPick_Params;
 struct ViewContext;
 struct rcti;
 struct TransVertStore;
diff --git a/source/blender/editors/include/ED_gizmo_library.hh b/source/blender/editors/include/ED_gizmo_library.hh
index 335104217de..c847334cbcf 100644
--- a/source/blender/editors/include/ED_gizmo_library.hh
+++ b/source/blender/editors/include/ED_gizmo_library.hh
@@ -14,7 +14,6 @@
 
 #include "DNA_scene_types.h"
 
-struct Object;
 struct bContext;
 struct wmGizmo;
 struct SnapObjectContext;
diff --git a/source/blender/editors/include/ED_grease_pencil.hh b/source/blender/editors/include/ED_grease_pencil.hh
index 57702707a63..95b9f033b81 100644
--- a/source/blender/editors/include/ED_grease_pencil.hh
+++ b/source/blender/editors/include/ED_grease_pencil.hh
@@ -41,7 +41,6 @@ namespace bke {
 enum class AttrDomain : int8_t;
 class CurvesGeometry;
 namespace crazyspace {
-struct GeometryDeformation;
 }
 }  // namespace bke
 }  // namespace blender
diff --git a/source/blender/editors/include/ED_keyframing.hh b/source/blender/editors/include/ED_keyframing.hh
index d3250fc09c1..6727399cba0 100644
--- a/source/blender/editors/include/ED_keyframing.hh
+++ b/source/blender/editors/include/ED_keyframing.hh
@@ -13,18 +13,13 @@
 #include "RNA_types.hh"
 
 struct ID;
-struct ListBase;
 struct Main;
 struct Scene;
 
 struct KeyingSet;
 
 struct AnimationEvalContext;
-struct BezTriple;
 struct FCurve;
-struct bAction;
-
-struct bPoseChannel;
 
 struct ReportList;
 struct bContext;
@@ -33,8 +28,6 @@ struct EnumPropertyItem;
 struct PointerRNA;
 struct PropertyRNA;
 
-struct NlaKeyframingContext;
-
 namespace blender::animrig {
 enum class ModifyKeyReturn;
 enum class ModifyKeyMode;
diff --git a/source/blender/editors/include/ED_lattice.hh b/source/blender/editors/include/ED_lattice.hh
index 52f42d12a29..7d591b65c5f 100644
--- a/source/blender/editors/include/ED_lattice.hh
+++ b/source/blender/editors/include/ED_lattice.hh
@@ -8,7 +8,6 @@
 
 #pragma once
 
-struct Base;
 struct KeyBlock;
 struct Lattice;
 struct Object;
diff --git a/source/blender/editors/include/ED_mesh.hh b/source/blender/editors/include/ED_mesh.hh
index 05ee4a8ff35..ceb25557409 100644
--- a/source/blender/editors/include/ED_mesh.hh
+++ b/source/blender/editors/include/ED_mesh.hh
@@ -24,7 +24,6 @@ struct BMesh;
 struct BMeshNormalsUpdate_Params;
 struct Base;
 struct Depsgraph;
-struct ID;
 struct KeyBlock;
 struct MDeformVert;
 struct Mesh;
@@ -38,7 +37,6 @@ struct UvVertMap;
 struct View3D;
 struct ViewContext;
 struct bContext;
-struct bDeformGroup;
 struct wmKeyConfig;
 struct wmOperator;
 struct UvElement;
diff --git a/source/blender/editors/include/ED_object.hh b/source/blender/editors/include/ED_object.hh
index 7e01532e894..106e55394db 100644
--- a/source/blender/editors/include/ED_object.hh
+++ b/source/blender/editors/include/ED_object.hh
@@ -27,7 +27,6 @@ struct Main;
 struct ModifierData;
 struct Object;
 struct PointerRNA;
-struct PropertyRNA;
 struct ReportList;
 struct Scene;
 struct ShaderFxData;
diff --git a/source/blender/editors/include/ED_sculpt.hh b/source/blender/editors/include/ED_sculpt.hh
index ba0bc603aca..2bcf7771b8f 100644
--- a/source/blender/editors/include/ED_sculpt.hh
+++ b/source/blender/editors/include/ED_sculpt.hh
@@ -8,13 +8,10 @@
 
 #pragma once
 
-struct ARegion;
 struct Object;
 struct ReportList;
 struct UndoType;
-struct ViewContext;
 struct bContext;
-struct rcti;
 struct wmOperator;
 struct wmKeyConfig;
 
diff --git a/source/blender/editors/include/UI_abstract_view.hh b/source/blender/editors/include/UI_abstract_view.hh
index fcb0bb44065..f20e584ba83 100644
--- a/source/blender/editors/include/UI_abstract_view.hh
+++ b/source/blender/editors/include/UI_abstract_view.hh
@@ -39,7 +39,6 @@ struct uiBlock;
 struct uiButViewItem;
 struct uiLayout;
 struct ViewLink;
-struct wmDrag;
 struct wmNotifier;
 
 namespace blender::ui {
diff --git a/source/blender/editors/include/UI_grid_view.hh b/source/blender/editors/include/UI_grid_view.hh
index 796d20a9e36..360f3f39ef1 100644
--- a/source/blender/editors/include/UI_grid_view.hh
+++ b/source/blender/editors/include/UI_grid_view.hh
@@ -21,9 +21,7 @@
 #include "UI_resources.hh"
 
 struct bContext;
-struct PointerRNA;
 struct uiBlock;
-struct uiButViewItem;
 struct uiLayout;
 struct View2D;
 
diff --git a/source/blender/editors/include/UI_interface_c.hh b/source/blender/editors/include/UI_interface_c.hh
index d2d73508b4c..11064ce2e2c 100644
--- a/source/blender/editors/include/UI_interface_c.hh
+++ b/source/blender/editors/include/UI_interface_c.hh
@@ -3382,7 +3382,6 @@ void UI_but_ensure_in_view(const bContext *C, ARegion *region, const uiBut *but)
 
 /* UI_butstore_ helpers */
 struct uiButStore;
-struct uiButStoreElem;
 
 /**
  * Create a new button store, the caller must manage and run #UI_butstore_free
diff --git a/source/blender/editors/include/UI_interface_icons.hh b/source/blender/editors/include/UI_interface_icons.hh
index fffadc95cb1..7704a9bed4e 100644
--- a/source/blender/editors/include/UI_interface_icons.hh
+++ b/source/blender/editors/include/UI_interface_icons.hh
@@ -16,7 +16,6 @@
 struct Collection;
 struct ID;
 struct ImBuf;
-struct ListBase;
 struct PointerRNA;
 struct PreviewImage;
 struct Scene;
diff --git a/source/blender/editors/include/UI_tree_view.hh b/source/blender/editors/include/UI_tree_view.hh
index 2846dd9afa3..92b9abb18bb 100644
--- a/source/blender/editors/include/UI_tree_view.hh
+++ b/source/blender/editors/include/UI_tree_view.hh
@@ -24,7 +24,6 @@
 
 struct bContext;
 struct uiBlock;
-struct uiBut;
 struct uiLayout;
 
 namespace blender::ui {
diff --git a/source/blender/editors/include/UI_view2d.hh b/source/blender/editors/include/UI_view2d.hh
index 2679d81d5a9..d46364617e9 100644
--- a/source/blender/editors/include/UI_view2d.hh
+++ b/source/blender/editors/include/UI_view2d.hh
@@ -104,7 +104,6 @@ enum eView2D_CommonViewTypes {
  * \{ */
 
 struct View2D;
-struct View2DScrollers;
 
 struct ARegion;
 struct Scene;
diff --git a/source/blender/editors/io/io_grease_pencil.hh b/source/blender/editors/io/io_grease_pencil.hh
index 9c207a4e2f9..5085fe56937 100644
--- a/source/blender/editors/io/io_grease_pencil.hh
+++ b/source/blender/editors/io/io_grease_pencil.hh
@@ -8,9 +8,6 @@
 
 #pragma once
 
-struct ARegion;
-struct View3D;
-struct bContext;
 struct wmOperatorType;
 
 void WM_OT_grease_pencil_import_svg(wmOperatorType *ot);
diff --git a/source/blender/editors/io/io_utils.hh b/source/blender/editors/io/io_utils.hh
index 7a1235d774a..0b304623157 100644
--- a/source/blender/editors/io/io_utils.hh
+++ b/source/blender/editors/io/io_utils.hh
@@ -9,12 +9,8 @@
 #include "BLI_vector.hh"
 
 struct wmOperator;
-struct wmOperatorType;
-struct wmDrag;
-struct wmDropBox;
 
 namespace blender::bke {
-struct FileHanlderType;
 }  // namespace blender::bke
 
 namespace blender::ed::io {
diff --git a/source/blender/editors/sculpt_paint/mesh_brush_common.hh b/source/blender/editors/sculpt_paint/mesh_brush_common.hh
index 5b06b4b09e4..b41913b6c69 100644
--- a/source/blender/editors/sculpt_paint/mesh_brush_common.hh
+++ b/source/blender/editors/sculpt_paint/mesh_brush_common.hh
@@ -44,7 +44,6 @@ struct Sculpt;
 struct SculptSession;
 struct SubdivCCG;
 struct SubdivCCGCoord;
-struct SubdivCCGNeighbors;
 namespace blender {
 namespace bke::pbvh {
 class Node;
diff --git a/source/blender/editors/sculpt_paint/paint_intern.hh b/source/blender/editors/sculpt_paint/paint_intern.hh
index b0f78f251ec..f405dd42ec6 100644
--- a/source/blender/editors/sculpt_paint/paint_intern.hh
+++ b/source/blender/editors/sculpt_paint/paint_intern.hh
@@ -25,13 +25,8 @@ enum class PaintMode : int8_t;
 
 struct ARegion;
 struct bContext;
-struct BMesh;
-struct BMVert;
 struct Brush;
-struct CCGElem;
-struct CCGKey;
 struct ColorManagedDisplay;
-struct ColorSpace;
 struct Depsgraph;
 struct Image;
 struct ImagePool;
@@ -47,7 +42,6 @@ struct ReportList;
 struct Scene;
 struct SculptSession;
 struct SpaceImage;
-struct SubdivCCG;
 struct ToolSettings;
 struct VertProjHandle;
 struct ViewContext;
diff --git a/source/blender/editors/sculpt_paint/sculpt_boundary.hh b/source/blender/editors/sculpt_paint/sculpt_boundary.hh
index 432e0c26e75..77e0a2087e0 100644
--- a/source/blender/editors/sculpt_paint/sculpt_boundary.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_boundary.hh
@@ -22,7 +22,6 @@ struct BMVert;
 struct Depsgraph;
 struct Object;
 struct PBVHVertRef;
-struct Sculpt;
 struct SculptBoundaryPreview;
 struct SculptSession;
 struct SubdivCCG;
diff --git a/source/blender/editors/sculpt_paint/sculpt_dyntopo.hh b/source/blender/editors/sculpt_paint/sculpt_dyntopo.hh
index bfc3ed100f2..85c6f961974 100644
--- a/source/blender/editors/sculpt_paint/sculpt_dyntopo.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_dyntopo.hh
@@ -17,7 +17,6 @@ struct Depsgraph;
 struct Main;
 struct Object;
 struct Scene;
-struct SculptSession;
 namespace blender::ed::sculpt_paint::undo {
 struct StepData;
 }
diff --git a/source/blender/editors/sculpt_paint/sculpt_face_set.hh b/source/blender/editors/sculpt_paint/sculpt_face_set.hh
index c42277b73f1..7255dbbc945 100644
--- a/source/blender/editors/sculpt_paint/sculpt_face_set.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_face_set.hh
@@ -19,7 +19,6 @@ struct BMVert;
 struct Mesh;
 struct Object;
 struct PBVHVertRef;
-struct SculptSession;
 struct SubdivCCG;
 struct SubdivCCGCoord;
 
diff --git a/source/blender/editors/sculpt_paint/sculpt_flood_fill.hh b/source/blender/editors/sculpt_paint/sculpt_flood_fill.hh
index b20ed617419..b6c6b063729 100644
--- a/source/blender/editors/sculpt_paint/sculpt_flood_fill.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_flood_fill.hh
@@ -17,9 +17,9 @@
 #include "BKE_pbvh.hh"
 #include "BKE_subdiv_ccg.hh"
 
+struct BMVert;
 struct Depsgraph;
 struct Object;
-struct SculptSession;
 
 namespace blender::ed::sculpt_paint::flood_fill {
 
diff --git a/source/blender/editors/sculpt_paint/sculpt_geodesic.hh b/source/blender/editors/sculpt_paint/sculpt_geodesic.hh
index cc95fcd85b9..043e972d82b 100644
--- a/source/blender/editors/sculpt_paint/sculpt_geodesic.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_geodesic.hh
@@ -11,10 +11,6 @@
 #include "BLI_array.hh"
 #include "BLI_set.hh"
 
-struct Depsgraph;
-struct Object;
-struct PBVHVertRef;
-
 namespace blender::ed::sculpt_paint::geodesic {
 
 /**
diff --git a/source/blender/editors/sculpt_paint/sculpt_intern.hh b/source/blender/editors/sculpt_paint/sculpt_intern.hh
index 30120cebda8..897707fa028 100644
--- a/source/blender/editors/sculpt_paint/sculpt_intern.hh
+++ b/source/blender/editors/sculpt_paint/sculpt_intern.hh
@@ -31,7 +31,6 @@
 
 namespace blender::ed::sculpt_paint {
 namespace auto_mask {
-struct NodeData;
 struct Cache;
 }
 namespace boundary {
@@ -45,7 +44,6 @@ struct IKChain;
 }
 namespace undo {
 struct Node;
-struct StepData;
 enum class Type : int8_t;
 }
 }
@@ -56,14 +54,10 @@ struct Image;
 struct ImageUser;
 struct KeyBlock;
 struct Object;
-struct SculptProjectVector;
 struct bContext;
 struct PaintModeSettings;
-struct WeightPaintInfo;
-struct WPaintData;
 struct wmKeyConfig;
 struct wmKeyMap;
-struct wmOperator;
 struct wmOperatorType;
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/editors/space_clip/clip_intern.hh b/source/blender/editors/space_clip/clip_intern.hh
index 4cff23c5e8c..74163f23f2d 100644
--- a/source/blender/editors/space_clip/clip_intern.hh
+++ b/source/blender/editors/space_clip/clip_intern.hh
@@ -18,7 +18,6 @@ struct MovieClip;
 struct MovieTrackingMarker;
 struct MovieTrackingTrack;
 struct Scene;
-struct ScrArea;
 struct SpaceClip;
 struct bContext;
 struct wmOperatorType;
diff --git a/source/blender/editors/space_outliner/outliner_intern.hh b/source/blender/editors/space_outliner/outliner_intern.hh
index 6242959c032..7a4be5ca2c1 100644
--- a/source/blender/editors/space_outliner/outliner_intern.hh
+++ b/source/blender/editors/space_outliner/outliner_intern.hh
@@ -20,28 +20,19 @@
 /* internal exports only */
 
 struct ARegion;
-struct Bone;
 struct Collection;
 struct EditBone;
-struct GpencilModifierData;
 struct ID;
 struct LayerCollection;
 struct ListBase;
 struct Main;
-struct ModifierData;
-struct ModifierDataStoreElem;
 struct Object;
 struct Scene;
-struct ShaderFxData;
 struct TreeStoreElem;
 struct ViewLayer;
-struct bActionGroup;
-struct bConstraint;
 struct bContext;
 struct bContextDataResult;
-struct bDeformGroup;
 struct bPoseChannel;
-struct ParticleSystem;
 struct View2D;
 struct wmKeyConfig;
 struct wmOperatorType;
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh b/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
index d60c5cf9547..704f5804c8f 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_armature.hh
@@ -10,8 +10,6 @@
 
 #include "tree_element_id.hh"
 
-struct Bone;
-struct EditBone;
 struct bArmature;
 
 namespace blender::ed::outliner {
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
index ec1163c70cd..4246d02da95 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_mesh.hh
@@ -10,6 +10,8 @@
 
 #include "tree_element_id.hh"
 
+struct Mesh;
+
 namespace blender::ed::outliner {
 
 class TreeElementIDMesh final : public TreeElementID {
diff --git a/source/blender/editors/space_outliner/tree/tree_element_id_object.cc b/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
index cd46b229a55..849617466c8 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_id_object.cc
@@ -20,6 +20,8 @@
 
 #include "tree_element_id_object.hh"
 
+struct bConstraint;
+
 namespace blender::ed::outliner {
 
 TreeElementIDObject::TreeElementIDObject(TreeElement &legacy_te, Object &object)
diff --git a/source/blender/editors/space_outliner/tree/tree_element_pose.cc b/source/blender/editors/space_outliner/tree/tree_element_pose.cc
index 5c9e1d6649a..ad0264dc169 100644
--- a/source/blender/editors/space_outliner/tree/tree_element_pose.cc
+++ b/source/blender/editors/space_outliner/tree/tree_element_pose.cc
@@ -18,6 +18,8 @@
 
 #include "tree_element_pose.hh"
 
+struct bConstraint;
+
 namespace blender::ed::outliner {
 
 TreeElementPoseBase::TreeElementPoseBase(TreeElement &legacy_te, Object &object)
diff --git a/source/blender/editors/space_sequencer/sequencer_intern.hh b/source/blender/editors/space_sequencer/sequencer_intern.hh
index f2f28927f2b..24e74b34229 100644
--- a/source/blender/editors/space_sequencer/sequencer_intern.hh
+++ b/source/blender/editors/space_sequencer/sequencer_intern.hh
@@ -29,10 +29,6 @@
 class SeqQuadsBatch;
 struct ARegion;
 struct ARegionType;
-struct Depsgraph;
-struct wmGizmoGroupType;
-struct wmGizmoType;
-struct Main;
 struct Scene;
 struct SeqRetimingKey;
 struct Sequence;
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh b/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
index 96c0257ba00..8da72fa6a73 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_intern.hh
@@ -8,7 +8,6 @@
 #include "spreadsheet_cache.hh"
 
 struct ARegionType;
-struct bContext;
 
 namespace blender::ed::spreadsheet {
 
diff --git a/source/blender/editors/space_view3d/view3d_intern.hh b/source/blender/editors/space_view3d/view3d_intern.hh
index b0cf2632656..389c2f548f8 100644
--- a/source/blender/editors/space_view3d/view3d_intern.hh
+++ b/source/blender/editors/space_view3d/view3d_intern.hh
@@ -18,8 +18,6 @@ struct BoundBox;
 struct Depsgraph;
 struct Object;
 struct Scene;
-struct ViewContext;
-struct ViewLayer;
 struct bContext;
 struct bContextDataResult;
 struct View3DCameraControl;
diff --git a/source/blender/editors/space_view3d/view3d_navigate.hh b/source/blender/editors/space_view3d/view3d_navigate.hh
index da321b831a1..08c817d2c67 100644
--- a/source/blender/editors/space_view3d/view3d_navigate.hh
+++ b/source/blender/editors/space_view3d/view3d_navigate.hh
@@ -29,7 +29,6 @@ struct PointerRNA;
 struct rcti;
 struct wmEvent;
 struct wmKeyConfig;
-struct wmKeyMap;
 struct wmOperator;
 struct wmOperatorType;
 struct wmTimer;
diff --git a/source/blender/geometry/GEO_mesh_primitive_line.hh b/source/blender/geometry/GEO_mesh_primitive_line.hh
index 65398f07816..7cd85c3ff3f 100644
--- a/source/blender/geometry/GEO_mesh_primitive_line.hh
+++ b/source/blender/geometry/GEO_mesh_primitive_line.hh
@@ -6,6 +6,8 @@
 
 #include "BLI_math_vector_types.hh"
 
+struct Mesh;
+
 namespace blender::geometry {
 
 Mesh *create_line_mesh(float3 start, float3 delta, int count);
diff --git a/source/blender/geometry/GEO_mesh_to_volume.hh b/source/blender/geometry/GEO_mesh_to_volume.hh
index 7fac24ba4af..38655fab70a 100644
--- a/source/blender/geometry/GEO_mesh_to_volume.hh
+++ b/source/blender/geometry/GEO_mesh_to_volume.hh
@@ -16,7 +16,6 @@
 #include "BKE_volume_grid_fwd.hh"
 
 struct Depsgraph;
-struct Mesh;
 struct Volume;
 
 /** \file
diff --git a/source/blender/gpu/GPU_material.hh b/source/blender/gpu/GPU_material.hh
index be6f2c787a0..0f0e2d4def8 100644
--- a/source/blender/gpu/GPU_material.hh
+++ b/source/blender/gpu/GPU_material.hh
@@ -21,7 +21,6 @@
 
 struct GHash;
 struct GPUMaterial;
-struct GPUNode;
 struct GPUNodeLink;
 struct GPUNodeStack;
 struct GPUPass;
diff --git a/source/blender/gpu/GPU_viewport.hh b/source/blender/gpu/GPU_viewport.hh
index 9177409178d..92c1757fdc5 100644
--- a/source/blender/gpu/GPU_viewport.hh
+++ b/source/blender/gpu/GPU_viewport.hh
@@ -19,7 +19,6 @@
 #define GLA_PIXEL_OFS 0.375f
 
 struct DRWData;
-struct GHash;
 struct GPUViewport;
 struct GPUFrameBuffer;
 struct GPUOffScreen;
diff --git a/source/blender/io/grease_pencil/intern/grease_pencil_io_intern.hh b/source/blender/io/grease_pencil/intern/grease_pencil_io_intern.hh
index 9c20ef1205f..38f2e3af94f 100644
--- a/source/blender/io/grease_pencil/intern/grease_pencil_io_intern.hh
+++ b/source/blender/io/grease_pencil/intern/grease_pencil_io_intern.hh
@@ -22,7 +22,6 @@
 
 struct Scene;
 struct Object;
-struct GreasePencil;
 struct Material;
 struct RegionView3D;
 namespace blender::bke::greasepencil {
diff --git a/source/blender/io/usd/intern/usd_blend_shape_utils.hh b/source/blender/io/usd/intern/usd_blend_shape_utils.hh
index c2557f9ed1b..e79b58a66f7 100644
--- a/source/blender/io/usd/intern/usd_blend_shape_utils.hh
+++ b/source/blender/io/usd/intern/usd_blend_shape_utils.hh
@@ -16,8 +16,6 @@ namespace blender::io::usd {
  * to the bound skeleton. */
 extern pxr::TfToken TempBlendShapeWeightsPrimvarName;
 
-struct ImportSettings;
-
 /**
  * Return the shape key on the given mesh object.
  *
diff --git a/source/blender/io/usd/intern/usd_skel_convert.hh b/source/blender/io/usd/intern/usd_skel_convert.hh
index 86cc77b2887..21cbbcef7d0 100644
--- a/source/blender/io/usd/intern/usd_skel_convert.hh
+++ b/source/blender/io/usd/intern/usd_skel_convert.hh
@@ -11,7 +11,6 @@
 #include <pxr/usd/usdSkel/bindingAPI.h>
 
 struct Depsgraph;
-struct Key;
 struct Main;
 struct Mesh;
 struct Object;
@@ -19,8 +18,6 @@ struct ReportList;
 
 namespace blender::io::usd {
 
-struct ImportSettings;
-
 /**
  * This file contains utilities for converting between `UsdSkel` data and
  * Blender armatures and shape keys. The following is a reference on the
diff --git a/source/blender/io/usd/intern/usd_writer_mesh.hh b/source/blender/io/usd/intern/usd_writer_mesh.hh
index e8759870223..3911cc265eb 100644
--- a/source/blender/io/usd/intern/usd_writer_mesh.hh
+++ b/source/blender/io/usd/intern/usd_writer_mesh.hh
@@ -9,7 +9,6 @@
 
 #include <pxr/usd/usdGeom/mesh.h>
 
-struct Key;
 struct SubsurfModifierData;
 
 namespace blender::bke {
diff --git a/source/blender/makesdna/DNA_ID.h b/source/blender/makesdna/DNA_ID.h
index a4a4487a6c4..5becd524ef6 100644
--- a/source/blender/makesdna/DNA_ID.h
+++ b/source/blender/makesdna/DNA_ID.h
@@ -28,7 +28,6 @@ extern "C" {
 
 struct FileData;
 struct GHash;
-struct GPUTexture;
 struct ID;
 struct Library;
 struct PackedFile;
diff --git a/source/blender/makesdna/DNA_action_types.h b/source/blender/makesdna/DNA_action_types.h
index 72b44230b15..c238d83dcba 100644
--- a/source/blender/makesdna/DNA_action_types.h
+++ b/source/blender/makesdna/DNA_action_types.h
@@ -45,7 +45,6 @@ typedef struct GPUVertBufHandle GPUVertBufHandle;
 /* Forward declarations so the actual declarations can happen top-down. */
 struct ActionLayer;
 struct ActionSlot;
-struct ActionSlot_runtime;
 struct ActionStrip;
 struct ActionChannelBag;
 
diff --git a/source/blender/makesdna/DNA_grease_pencil_types.h b/source/blender/makesdna/DNA_grease_pencil_types.h
index 6c09b6bba33..6e890c28ec5 100644
--- a/source/blender/makesdna/DNA_grease_pencil_types.h
+++ b/source/blender/makesdna/DNA_grease_pencil_types.h
@@ -50,10 +50,7 @@ typedef struct GreasePencilLayerGroupRuntimeHandle GreasePencilLayerGroupRuntime
 
 struct Main;
 struct GreasePencil;
-struct BlendDataReader;
-struct BlendWriter;
 struct Object;
-struct bDeformGroup;
 
 typedef enum GreasePencilStrokeCapType {
   GP_STROKE_CAP_TYPE_ROUND = 0,
diff --git a/source/blender/makesdna/DNA_light_types.h b/source/blender/makesdna/DNA_light_types.h
index 821764ca8b8..4609a042d42 100644
--- a/source/blender/makesdna/DNA_light_types.h
+++ b/source/blender/makesdna/DNA_light_types.h
@@ -16,7 +16,6 @@
 #endif
 
 struct AnimData;
-struct CurveMapping;
 struct Ipo;
 struct bNodeTree;
 
diff --git a/source/blender/makesdna/DNA_node_tree_interface_types.h b/source/blender/makesdna/DNA_node_tree_interface_types.h
index 3d9793f7062..8110759a379 100644
--- a/source/blender/makesdna/DNA_node_tree_interface_types.h
+++ b/source/blender/makesdna/DNA_node_tree_interface_types.h
@@ -31,7 +31,6 @@ typedef struct bNodeTreeInterfaceRuntimeHandle bNodeTreeInterfaceRuntimeHandle;
 typedef struct bNodeSocketTypeHandle bNodeSocketTypeHandle;
 #endif
 
-struct bContext;
 struct bNodeSocket;
 struct bNodeTreeInterfaceItem;
 struct bNodeTreeInterfacePanel;
@@ -39,11 +38,8 @@ struct bNodeTreeInterfaceSocket;
 struct ID;
 struct IDProperty;
 struct LibraryForeachIDData;
-struct PointerRNA;
-struct uiLayout;
 struct BlendWriter;
 struct BlendDataReader;
-struct BlendLibReader;
 
 /** Type of interface item. */
 typedef enum NodeTreeInterfaceItemType {
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 5bb054b53a1..f3758069687 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -34,7 +34,6 @@ namespace blender::bke {
 class bNodeTreeRuntime;
 class bNodeRuntime;
 class bNodeSocketRuntime;
-struct bNodeTreeInterfaceCache;
 }  // namespace blender::bke
 namespace blender::bke {
 class bNodeTreeZones;
diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index 20d76e4a556..434e7201067 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -44,9 +44,7 @@ struct Curve;
 struct FluidsimSettings;
 struct Ipo;
 struct LightgroupMembership;
-struct LightProbeGridCacheFrame;
 struct Material;
-struct Mesh;
 struct Object;
 struct PartDeflect;
 struct Path;
diff --git a/source/blender/makesrna/RNA_enum_types.hh b/source/blender/makesrna/RNA_enum_types.hh
index 2a36ddb2acf..dc84c171f4e 100644
--- a/source/blender/makesrna/RNA_enum_types.hh
+++ b/source/blender/makesrna/RNA_enum_types.hh
@@ -19,7 +19,6 @@ struct PropertyRNA;
 struct bContext;
 namespace blender::bke {
 struct bNodeTreeType;
-struct bNodeType;
 struct bNodeSocketType;
 struct RuntimeNodeEnumItems;
 }  // namespace blender::bke
diff --git a/source/blender/makesrna/intern/rna_internal.hh b/source/blender/makesrna/intern/rna_internal.hh
index 44a0dcfc0a2..04d50dee954 100644
--- a/source/blender/makesrna/intern/rna_internal.hh
+++ b/source/blender/makesrna/intern/rna_internal.hh
@@ -22,7 +22,6 @@ enum class AttributeOwnerType;
 
 struct FreestyleSettings;
 struct ID;
-struct IDOverrideLibrary;
 struct IDProperty;
 struct FreestyleLineSet;
 struct FreestyleModuleConfig;
diff --git a/source/blender/modifiers/intern/MOD_grease_pencil_util.hh b/source/blender/modifiers/intern/MOD_grease_pencil_util.hh
index c1d93f1bf00..4b374f85b4a 100644
--- a/source/blender/modifiers/intern/MOD_grease_pencil_util.hh
+++ b/source/blender/modifiers/intern/MOD_grease_pencil_util.hh
@@ -13,13 +13,9 @@
 
 #include "BKE_modifier.hh"
 
-struct ARegionType;
 struct bContext;
 struct GreasePencil;
 struct GreasePencilModifierInfluenceData;
-struct GreasePencilModifierLayerFilter;
-struct GreasePencilModifierMaterialFilter;
-struct PanelType;
 struct PointerRNA;
 struct uiLayout;
 namespace blender::bke {
diff --git a/source/blender/nodes/NOD_geometry_nodes_execute.hh b/source/blender/nodes/NOD_geometry_nodes_execute.hh
index 106e9a31c7d..38ec63db083 100644
--- a/source/blender/nodes/NOD_geometry_nodes_execute.hh
+++ b/source/blender/nodes/NOD_geometry_nodes_execute.hh
@@ -13,14 +13,11 @@
 #include "BKE_node.hh"
 
 struct bNodeTree;
-struct bNodeSocket;
 struct bNodeTreeInterfaceSocket;
-struct Depsgraph;
 namespace blender::bke {
 struct GeometrySet;
 }
 struct IDProperty;
-struct Object;
 namespace blender::nodes {
 struct GeoNodesCallData;
 namespace geo_eval_log {
diff --git a/source/blender/nodes/geometry/node_geometry_util.hh b/source/blender/nodes/geometry/node_geometry_util.hh
index 32908347f9d..6b79ed194dd 100644
--- a/source/blender/nodes/geometry/node_geometry_util.hh
+++ b/source/blender/nodes/geometry/node_geometry_util.hh
@@ -17,7 +17,6 @@
 #include "node_util.hh"
 
 struct BVHTreeFromMesh;
-struct GeometrySet;
 namespace blender::nodes {
 class GatherAddNodeSearchParams;
 class GatherLinkSearchOpParams;
diff --git a/source/blender/nodes/shader/node_shader_util.hh b/source/blender/nodes/shader/node_shader_util.hh
index 454084c472b..ac878666b73 100644
--- a/source/blender/nodes/shader/node_shader_util.hh
+++ b/source/blender/nodes/shader/node_shader_util.hh
@@ -31,7 +31,6 @@
 
 struct bContext;
 struct bNodeExecContext;
-struct bNodeExecData;
 struct bNodeTreeExec;
 struct GPUNodeLink;
 struct GPUNodeStack;
diff --git a/source/blender/render/RE_compositor.hh b/source/blender/render/RE_compositor.hh
index a9501700f01..d68412f4304 100644
--- a/source/blender/render/RE_compositor.hh
+++ b/source/blender/render/RE_compositor.hh
@@ -12,7 +12,6 @@ class Profiler;
 }  // namespace blender::realtime_compositor
 
 struct bNodeTree;
-struct Depsgraph;
 struct Render;
 struct RenderData;
 struct Scene;
diff --git a/source/blender/render/hydra/camera.hh b/source/blender/render/hydra/camera.hh
index 2cba61272b9..f259a73990d 100644
--- a/source/blender/render/hydra/camera.hh
+++ b/source/blender/render/hydra/camera.hh
@@ -11,7 +11,6 @@ struct ARegion;
 struct Object;
 struct View3D;
 struct Depsgraph;
-struct RenderData;
 
 namespace blender::render::hydra {
 
diff --git a/source/blender/render/intern/render_types.h b/source/blender/render/intern/render_types.h
index 9df52be090c..8737ad9b1ab 100644
--- a/source/blender/render/intern/render_types.h
+++ b/source/blender/render/intern/render_types.h
@@ -30,7 +30,6 @@ class Profiler;
 
 struct bNodeTree;
 struct Depsgraph;
-struct GSet;
 struct Main;
 struct Object;
 struct RenderEngine;
diff --git a/source/blender/sequencer/SEQ_modifier.hh b/source/blender/sequencer/SEQ_modifier.hh
index f2ec204a318..a013f537b4a 100644
--- a/source/blender/sequencer/SEQ_modifier.hh
+++ b/source/blender/sequencer/SEQ_modifier.hh
@@ -9,11 +9,9 @@
  */
 
 struct BlendDataReader;
-struct BlendLibReader;
 struct BlendWriter;
 struct ImBuf;
 struct ListBase;
-struct Scene;
 struct SeqRenderData;
 struct Sequence;
 struct SequenceModifierData;
diff --git a/source/blender/sequencer/SEQ_render.hh b/source/blender/sequencer/SEQ_render.hh
index b092885657d..d1feabef3b8 100644
--- a/source/blender/sequencer/SEQ_render.hh
+++ b/source/blender/sequencer/SEQ_render.hh
@@ -17,7 +17,6 @@ struct Main;
 struct Scene;
 struct Sequence;
 struct StripElem;
-struct rctf;
 
 enum eSeqTaskId {
   SEQ_TASK_MAIN_RENDER,
diff --git a/source/blender/sequencer/SEQ_sequencer.hh b/source/blender/sequencer/SEQ_sequencer.hh
index 6774528b6a6..85f146fb75b 100644
--- a/source/blender/sequencer/SEQ_sequencer.hh
+++ b/source/blender/sequencer/SEQ_sequencer.hh
@@ -11,7 +11,6 @@
 #include "DNA_scene_types.h"
 
 struct BlendDataReader;
-struct BlendLibReader;
 struct BlendWriter;
 struct Depsgraph;
 struct Editing;
diff --git a/source/blender/sequencer/SEQ_sound.hh b/source/blender/sequencer/SEQ_sound.hh
index 8c5aabfa7dc..7ec029c2c1b 100644
--- a/source/blender/sequencer/SEQ_sound.hh
+++ b/source/blender/sequencer/SEQ_sound.hh
@@ -14,7 +14,6 @@ struct Scene;
 struct Sequence;
 struct bSound;
 struct SequenceModifierData;
-struct SequencerSoundEqualizer;
 struct SoundModifierWorkerInfo;
 struct BlendWriter;
 struct BlendDataReader;
diff --git a/source/blender/sequencer/intern/image_cache.hh b/source/blender/sequencer/intern/image_cache.hh
index 08ee021a537..1f7a07c5c95 100644
--- a/source/blender/sequencer/intern/image_cache.hh
+++ b/source/blender/sequencer/intern/image_cache.hh
@@ -11,7 +11,6 @@
 #include "SEQ_render.hh" /* Needed for #eSeqTaskId. */
 
 struct ImBuf;
-struct Main;
 struct Scene;
 struct SeqCache;
 struct SeqRenderData;
diff --git a/source/blender/sequencer/intern/strip_time.hh b/source/blender/sequencer/intern/strip_time.hh
index e9bd6a60d2d..b750d17bc58 100644
--- a/source/blender/sequencer/intern/strip_time.hh
+++ b/source/blender/sequencer/intern/strip_time.hh
@@ -13,7 +13,6 @@
 struct ListBase;
 struct Scene;
 struct Sequence;
-struct SeqCollection;
 
 void seq_update_sound_bounds_recursive(const Scene *scene, Sequence *metaseq);
 
diff --git a/source/blender/windowmanager/WM_api.hh b/source/blender/windowmanager/WM_api.hh
index 6fe17593137..c11d23e8abc 100644
--- a/source/blender/windowmanager/WM_api.hh
+++ b/source/blender/windowmanager/WM_api.hh
@@ -57,9 +57,6 @@ struct wmEventHandler_Op;
 struct wmEventHandler_UI;
 struct wmGenericUserData;
 struct wmGesture;
-struct wmGizmo;
-struct wmGizmoMap;
-struct wmGizmoMapType;
 struct wmJob;
 struct wmJobWorkerStatus;
 struct wmOperator;