diff --git a/source/blender/asset_system/AS_asset_library.h b/source/blender/asset_system/AS_asset_library.h
index 0a67df2ecbf..870d2041655 100644
--- a/source/blender/asset_system/AS_asset_library.h
+++ b/source/blender/asset_system/AS_asset_library.h
@@ -7,7 +7,6 @@
 #pragma once
 
 struct IDRemapper;
-struct Main;
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/source/blender/blenfont/BLF_api.h b/source/blender/blenfont/BLF_api.h
index 01b6d1d8942..558fd5f1dc2 100644
--- a/source/blender/blenfont/BLF_api.h
+++ b/source/blender/blenfont/BLF_api.h
@@ -28,7 +28,6 @@ extern "C" {
 
 struct ColorManagedDisplay;
 struct ResultBLF;
-struct rctf;
 struct rcti;
 
 int BLF_init(void);
diff --git a/source/blender/blenfont/intern/blf_internal.h b/source/blender/blenfont/intern/blf_internal.h
index 2f3f7b52233..cbdfa191877 100644
--- a/source/blender/blenfont/intern/blf_internal.h
+++ b/source/blender/blenfont/intern/blf_internal.h
@@ -11,7 +11,6 @@ struct FontBLF;
 struct GlyphBLF;
 struct GlyphCacheBLF;
 struct ResultBLF;
-struct rctf;
 struct rcti;
 
 /* Max number of FontBLFs in memory. Take care that every font has a glyph cache per size/dpi,
diff --git a/source/blender/blenkernel/BKE_animsys.h b/source/blender/blenkernel/BKE_animsys.h
index 91ecfe09f38..46aacf1e7fd 100644
--- a/source/blender/blenkernel/BKE_animsys.h
+++ b/source/blender/blenkernel/BKE_animsys.h
@@ -33,7 +33,6 @@ struct PointerRNA;
 struct PropertyRNA;
 struct bAction;
 struct bActionGroup;
-struct bContext;
 
 /* Container for data required to do FCurve and Driver evaluation. */
 typedef struct AnimationEvalContext {
diff --git a/source/blender/blenkernel/BKE_blendfile_link_append.h b/source/blender/blenkernel/BKE_blendfile_link_append.h
index bd00ed51d99..0f54760e03a 100644
--- a/source/blender/blenkernel/BKE_blendfile_link_append.h
+++ b/source/blender/blenkernel/BKE_blendfile_link_append.h
@@ -13,11 +13,7 @@ struct BlendHandle;
 struct ID;
 struct Library;
 struct LibraryLink_Params;
-struct Main;
 struct ReportList;
-struct Scene;
-struct View3D;
-struct ViewLayer;
 
 typedef struct BlendfileLinkAppendContext BlendfileLinkAppendContext;
 typedef struct BlendfileLinkAppendContextItem BlendfileLinkAppendContextItem;
diff --git a/source/blender/blenkernel/BKE_bpath.h b/source/blender/blenkernel/BKE_bpath.h
index 555cddd34bd..20fd0758370 100644
--- a/source/blender/blenkernel/BKE_bpath.h
+++ b/source/blender/blenkernel/BKE_bpath.h
@@ -19,7 +19,6 @@ extern "C" {
 #endif
 
 struct ID;
-struct ListBase;
 struct Main;
 struct ReportList;
 
diff --git a/source/blender/blenkernel/BKE_brush.h b/source/blender/blenkernel/BKE_brush.h
index a763b3d12c2..369b7e56a6c 100644
--- a/source/blender/blenkernel/BKE_brush.h
+++ b/source/blender/blenkernel/BKE_brush.h
@@ -18,7 +18,6 @@ extern "C" {
 struct Brush;
 struct ImBuf;
 struct ImagePool;
-struct Object;
 struct Main;
 struct MTex;
 struct Scene;
diff --git a/source/blender/blenkernel/BKE_collision.h b/source/blender/blenkernel/BKE_collision.h
index 01e0a0ce062..8e566f08b5d 100644
--- a/source/blender/blenkernel/BKE_collision.h
+++ b/source/blender/blenkernel/BKE_collision.h
@@ -16,7 +16,6 @@ struct CollisionModifierData;
 struct Depsgraph;
 struct MVertTri;
 struct Object;
-struct Scene;
 
 ////////////////////////////////////////
 // used for collisions in collision.c
diff --git a/source/blender/blenkernel/BKE_curves.h b/source/blender/blenkernel/BKE_curves.h
index 71a0562e1df..83a0ba201f8 100644
--- a/source/blender/blenkernel/BKE_curves.h
+++ b/source/blender/blenkernel/BKE_curves.h
@@ -15,7 +15,6 @@ extern "C" {
 
 struct BoundBox;
 struct Curves;
-struct CustomDataLayer;
 struct Depsgraph;
 struct Main;
 struct Object;
diff --git a/source/blender/blenkernel/BKE_displist.h b/source/blender/blenkernel/BKE_displist.h
index 6551e732300..410cc0b473a 100644
--- a/source/blender/blenkernel/BKE_displist.h
+++ b/source/blender/blenkernel/BKE_displist.h
@@ -43,7 +43,6 @@ enum {
 
 struct Depsgraph;
 struct ListBase;
-struct Mesh;
 struct Object;
 struct Scene;
 
diff --git a/source/blender/blenkernel/BKE_geometry_set.h b/source/blender/blenkernel/BKE_geometry_set.h
index 97e69f3fe1f..c3403e66cab 100644
--- a/source/blender/blenkernel/BKE_geometry_set.h
+++ b/source/blender/blenkernel/BKE_geometry_set.h
@@ -10,7 +10,6 @@
 extern "C" {
 #endif
 
-struct Collection;
 struct GeometrySet;
 struct Object;
 
diff --git a/source/blender/blenkernel/BKE_geometry_set.hh b/source/blender/blenkernel/BKE_geometry_set.hh
index f450ffe33e8..72f77c889c1 100644
--- a/source/blender/blenkernel/BKE_geometry_set.hh
+++ b/source/blender/blenkernel/BKE_geometry_set.hh
@@ -20,10 +20,8 @@
 #include "BKE_geometry_set.h"
 
 struct Curves;
-struct Collection;
 struct Curve;
 struct Mesh;
-struct Object;
 struct PointCloud;
 struct Volume;
 
diff --git a/source/blender/blenkernel/BKE_gpencil.h b/source/blender/blenkernel/BKE_gpencil.h
index dc7a5ab003a..55ca1c38af4 100644
--- a/source/blender/blenkernel/BKE_gpencil.h
+++ b/source/blender/blenkernel/BKE_gpencil.h
@@ -16,7 +16,6 @@ struct Brush;
 struct CurveMapping;
 struct Depsgraph;
 struct GHash;
-struct GPencilUpdateCache;
 struct ListBase;
 struct MDeformVert;
 struct Main;
diff --git a/source/blender/blenkernel/BKE_gpencil_geom.h b/source/blender/blenkernel/BKE_gpencil_geom.h
index 976961f27ae..70b12477b43 100644
--- a/source/blender/blenkernel/BKE_gpencil_geom.h
+++ b/source/blender/blenkernel/BKE_gpencil_geom.h
@@ -14,7 +14,6 @@ extern "C" {
 struct Depsgraph;
 struct Main;
 struct Object;
-struct RegionView3D;
 struct Scene;
 struct bGPDcurve;
 struct bGPDframe;
diff --git a/source/blender/blenkernel/BKE_image.h b/source/blender/blenkernel/BKE_image.h
index eb43ce823ac..f00da370ccf 100644
--- a/source/blender/blenkernel/BKE_image.h
+++ b/source/blender/blenkernel/BKE_image.h
@@ -565,7 +565,6 @@ struct PartialUpdateUser *BKE_image_partial_update_create(const struct Image *im
 void BKE_image_partial_update_free(struct PartialUpdateUser *user);
 
 /* --- partial updater (image side) --- */
-struct PartialUpdateRegister;
 
 void BKE_image_partial_update_register_free(struct Image *image);
 /** \brief Mark a region of the image to update. */
diff --git a/source/blender/blenkernel/BKE_image_partial_update.hh b/source/blender/blenkernel/BKE_image_partial_update.hh
index 8f962ace268..8e914940b3a 100644
--- a/source/blender/blenkernel/BKE_image_partial_update.hh
+++ b/source/blender/blenkernel/BKE_image_partial_update.hh
@@ -23,7 +23,6 @@
 #include "DNA_image_types.h"
 
 extern "C" {
-struct PartialUpdateRegister;
 struct PartialUpdateUser;
 }
 
diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index dc595ff0ce1..557b70b8a11 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -40,7 +40,6 @@ struct MPoly;
 struct Main;
 struct MemArena;
 struct Mesh;
-struct ModifierData;
 struct Object;
 struct PointCloud;
 struct Scene;
diff --git a/source/blender/blenkernel/BKE_mesh_wrapper.h b/source/blender/blenkernel/BKE_mesh_wrapper.h
index b4742583b03..a9b9bb96178 100644
--- a/source/blender/blenkernel/BKE_mesh_wrapper.h
+++ b/source/blender/blenkernel/BKE_mesh_wrapper.h
@@ -8,7 +8,6 @@
 struct BMEditMesh;
 struct CustomData_MeshMasks;
 struct Mesh;
-struct Object;
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/source/blender/blenkernel/BKE_multires.h b/source/blender/blenkernel/BKE_multires.h
index 57e87ddddd8..5e5ca8b4ee6 100644
--- a/source/blender/blenkernel/BKE_multires.h
+++ b/source/blender/blenkernel/BKE_multires.h
@@ -24,8 +24,6 @@ struct Object;
 struct Scene;
 struct SubdivCCG;
 
-struct MLoop;
-struct MLoopTri;
 struct MPoly;
 
 /**
diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index c40839361e2..dc5b1791bdb 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -29,27 +29,19 @@ extern "C" {
 /* not very important, but the stack solver likes to know a maximum */
 #define MAX_SOCKET 512
 
-struct ARegion;
 struct BlendDataReader;
 struct BlendExpander;
 struct BlendLibReader;
 struct BlendWriter;
-struct ColorManagedDisplaySettings;
-struct ColorManagedViewSettings;
-struct CryptomatteSession;
 struct FreestyleLineStyle;
 struct GPUMaterial;
 struct GPUNodeStack;
 struct ID;
 struct ImBuf;
-struct ImageFormatData;
 struct Light;
-struct ListBase;
-struct MTex;
 struct Main;
 struct Material;
 struct PointerRNA;
-struct RenderData;
 struct Scene;
 struct SpaceNode;
 struct Tex;
@@ -1355,8 +1347,6 @@ void BKE_nodetree_remove_layer_n(struct bNodeTree *ntree, struct Scene *scene, i
 /** \name Texture Nodes
  * \{ */
 
-struct TexResult;
-
 #define TEX_NODE_OUTPUT 401
 #define TEX_NODE_CHECKER 402
 #define TEX_NODE_TEXTURE 403
diff --git a/source/blender/blenkernel/BKE_object.h b/source/blender/blenkernel/BKE_object.h
index 963b0b87118..c77faf98b25 100644
--- a/source/blender/blenkernel/BKE_object.h
+++ b/source/blender/blenkernel/BKE_object.h
@@ -20,7 +20,6 @@ struct Base;
 struct BoundBox;
 struct Curve;
 struct Depsgraph;
-struct GeometrySet;
 struct GpencilModifierData;
 struct HookGpencilModifierData;
 struct HookModifierData;
@@ -33,7 +32,6 @@ struct Object;
 struct RegionView3D;
 struct RigidBodyWorld;
 struct Scene;
-struct ShaderFxData;
 struct SubsurfModifierData;
 struct View3D;
 struct ViewLayer;
diff --git a/source/blender/blenkernel/BKE_particle.h b/source/blender/blenkernel/BKE_particle.h
index f295979f23c..ad7045a8c2e 100644
--- a/source/blender/blenkernel/BKE_particle.h
+++ b/source/blender/blenkernel/BKE_particle.h
@@ -31,7 +31,6 @@ struct CustomData_MeshMasks;
 struct Depsgraph;
 struct EdgeHash;
 struct KDTree_3d;
-struct LatticeDeformData;
 struct LinkNode;
 struct MCol;
 struct MFace;
diff --git a/source/blender/blenkernel/BKE_pointcloud.h b/source/blender/blenkernel/BKE_pointcloud.h
index 48be080968d..c6a72af6fab 100644
--- a/source/blender/blenkernel/BKE_pointcloud.h
+++ b/source/blender/blenkernel/BKE_pointcloud.h
@@ -20,7 +20,6 @@ extern "C" {
 #endif
 
 struct BoundBox;
-struct CustomDataLayer;
 struct Depsgraph;
 struct Main;
 struct Object;
diff --git a/source/blender/blenkernel/BKE_subsurf.h b/source/blender/blenkernel/BKE_subsurf.h
index 557a71fd06b..3630c95ec76 100644
--- a/source/blender/blenkernel/BKE_subsurf.h
+++ b/source/blender/blenkernel/BKE_subsurf.h
@@ -24,7 +24,6 @@ struct CCGVert;
 struct DMFlagMat;
 struct DerivedMesh;
 struct EdgeHash;
-struct MPoly;
 struct Mesh;
 struct MeshElemMap;
 struct Object;
diff --git a/source/blender/blenkernel/intern/library.c b/source/blender/blenkernel/intern/library.c
index 516fb9b75b6..ee50c4ae753 100644
--- a/source/blender/blenkernel/intern/library.c
+++ b/source/blender/blenkernel/intern/library.c
@@ -32,7 +32,6 @@
 /* Unused currently. */
 // static CLG_LogRef LOG = {.identifier = "bke.library"};
 
-struct BlendWriter;
 struct BlendDataReader;
 
 static void library_runtime_reset(Library *lib)
diff --git a/source/blender/blenkernel/intern/pbvh_uv_islands.hh b/source/blender/blenkernel/intern/pbvh_uv_islands.hh
index b97d07a2146..9496b564516 100644
--- a/source/blender/blenkernel/intern/pbvh_uv_islands.hh
+++ b/source/blender/blenkernel/intern/pbvh_uv_islands.hh
@@ -43,7 +43,6 @@ struct UVEdge;
 struct UVIslands;
 struct UVIslandsMask;
 struct UVPrimitive;
-struct UVPrimitiveEdge;
 struct MeshData;
 struct UVVertex;
 
diff --git a/source/blender/blenloader/BLO_read_write.h b/source/blender/blenloader/BLO_read_write.h
index 56b0cc81598..35768cb7e7a 100644
--- a/source/blender/blenloader/BLO_read_write.h
+++ b/source/blender/blenloader/BLO_read_write.h
@@ -42,7 +42,6 @@ typedef struct BlendWriter BlendWriter;
 
 struct BlendFileReadReport;
 struct Main;
-struct ReportList;
 
 /* -------------------------------------------------------------------- */
 /** \name Blend Write API
diff --git a/source/blender/blenloader/BLO_readfile.h b/source/blender/blenloader/BLO_readfile.h
index 4c34b628a6d..850aff20a1b 100644
--- a/source/blender/blenloader/BLO_readfile.h
+++ b/source/blender/blenloader/BLO_readfile.h
@@ -16,13 +16,11 @@ extern "C" {
 
 struct BHead;
 struct BlendThumbnail;
-struct Collection;
 struct FileData;
 struct LinkNode;
 struct ListBase;
 struct Main;
 struct MemFile;
-struct Object;
 struct ReportList;
 struct Scene;
 struct UserDef;
diff --git a/source/blender/blenloader/intern/readfile.h b/source/blender/blenloader/intern/readfile.h
index a0f19512753..027f1453581 100644
--- a/source/blender/blenloader/intern/readfile.h
+++ b/source/blender/blenloader/intern/readfile.h
@@ -23,7 +23,6 @@
 extern "C" {
 #endif
 
-struct BLI_mmap_file;
 struct BLOCacheStorage;
 struct IDNameLib_Map;
 struct Key;
diff --git a/source/blender/bmesh/intern/bmesh_mesh.h b/source/blender/bmesh/intern/bmesh_mesh.h
index d72ecfca338..a4cfa00aeb3 100644
--- a/source/blender/bmesh/intern/bmesh_mesh.h
+++ b/source/blender/bmesh/intern/bmesh_mesh.h
@@ -13,9 +13,6 @@ extern "C" {
 #endif
 
 struct BMAllocTemplate;
-struct BMLoopNorEditDataArray;
-struct BMPartialUpdate;
-struct MLoopNorSpaceArray;
 
 void BM_mesh_elem_toolflags_ensure(BMesh *bm);
 void BM_mesh_elem_toolflags_clear(BMesh *bm);
diff --git a/source/blender/bmesh/intern/bmesh_mesh_normals.h b/source/blender/bmesh/intern/bmesh_mesh_normals.h
index f92d7e3fbfd..51768af2ab0 100644
--- a/source/blender/bmesh/intern/bmesh_mesh_normals.h
+++ b/source/blender/bmesh/intern/bmesh_mesh_normals.h
@@ -12,6 +12,8 @@
 extern "C" {
 #endif
 
+struct BMPartialUpdate;
+
 struct BMeshNormalsUpdate_Params {
   /**
    * When calculating tessellation as well as normals, tessellate & calculate face normals
diff --git a/source/blender/bmesh/intern/bmesh_polygon.h b/source/blender/bmesh/intern/bmesh_polygon.h
index d9f48b4887b..6262f185eca 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.h
+++ b/source/blender/bmesh/intern/bmesh_polygon.h
@@ -6,7 +6,6 @@
  * \ingroup bmesh
  */
 
-struct BMPartialUpdate;
 struct Heap;
 
 #include "BLI_compiler_attrs.h"
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
index a8efe8fca9f..f944b836563 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.h
@@ -45,7 +45,6 @@ struct World;
 struct bAction;
 struct bArmature;
 struct bConstraint;
-struct bGPdata;
 struct bNodeSocket;
 struct bNodeTree;
 struct bPoseChannel;
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.h b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
index 901e4a1acbb..3473ac55a1e 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.h
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.h
@@ -62,7 +62,6 @@ struct World;
 struct bAction;
 struct bArmature;
 struct bConstraint;
-struct bGPdata;
 struct bNodeSocket;
 struct bNodeTree;
 struct bPoseChannel;
diff --git a/source/blender/draw/DRW_pbvh.h b/source/blender/draw/DRW_pbvh.h
index d49e5b6c686..00c76b641ee 100644
--- a/source/blender/draw/DRW_pbvh.h
+++ b/source/blender/draw/DRW_pbvh.h
@@ -17,17 +17,14 @@
 extern "C" {
 #endif
 
-struct GPUViewport;
 struct PBVHAttrReq;
 struct GPUBatch;
 struct PBVHNode;
 struct GSet;
 struct DMFlagMat;
-struct Object;
 struct Mesh;
 struct MLoopTri;
 struct CustomData;
-struct MEdge;
 struct MLoop;
 struct MPoly;
 struct SubdivCCG;
diff --git a/source/blender/draw/engines/eevee_next/eevee_cryptomatte.hh b/source/blender/draw/engines/eevee_next/eevee_cryptomatte.hh
index 86ab3d97b4b..daeb9a08e35 100644
--- a/source/blender/draw/engines/eevee_next/eevee_cryptomatte.hh
+++ b/source/blender/draw/engines/eevee_next/eevee_cryptomatte.hh
@@ -20,7 +20,6 @@
 
 extern "C" {
 struct Material;
-struct CryptomatteSession;
 }
 
 namespace blender::eevee {
diff --git a/source/blender/draw/engines/image/image_private.hh b/source/blender/draw/engines/image/image_private.hh
index 8241b7e288e..4780eea5bf5 100644
--- a/source/blender/draw/engines/image/image_private.hh
+++ b/source/blender/draw/engines/image/image_private.hh
@@ -16,8 +16,6 @@
 
 /* Forward declarations */
 extern "C" {
-struct GPUTexture;
-struct ImBuf;
 struct Image;
 }
 
diff --git a/source/blender/draw/intern/draw_cache_impl.h b/source/blender/draw/intern/draw_cache_impl.h
index 73ca5821ff0..8cc53b48af8 100644
--- a/source/blender/draw/intern/draw_cache_impl.h
+++ b/source/blender/draw/intern/draw_cache_impl.h
@@ -8,10 +8,8 @@
 #pragma once
 
 struct GPUBatch;
-struct GPUIndexBuf;
 struct GPUMaterial;
 struct GPUVertBuf;
-struct ListBase;
 struct ModifierData;
 struct PTCacheEdit;
 struct ParticleSystem;
@@ -21,7 +19,6 @@ struct Curve;
 struct Curves;
 struct Lattice;
 struct Mesh;
-struct MetaBall;
 struct PointCloud;
 struct Volume;
 struct bGPdata;
diff --git a/source/blender/draw/intern/draw_command_shared.hh b/source/blender/draw/intern/draw_command_shared.hh
index 9fbbe23f0ce..4bb9aa777f3 100644
--- a/source/blender/draw/intern/draw_command_shared.hh
+++ b/source/blender/draw/intern/draw_command_shared.hh
@@ -11,8 +11,6 @@
 
 namespace blender::draw::command {
 
-struct RecordingState;
-
 #endif
 
 /* -------------------------------------------------------------------- */
diff --git a/source/blender/draw/intern/draw_curves_private.h b/source/blender/draw/intern/draw_curves_private.h
index 36deca46e94..9d02eedbbc3 100644
--- a/source/blender/draw/intern/draw_curves_private.h
+++ b/source/blender/draw/intern/draw_curves_private.h
@@ -18,9 +18,7 @@ extern "C" {
 
 struct Curves;
 struct GPUVertBuf;
-struct GPUIndexBuf;
 struct GPUBatch;
-struct GPUTexture;
 
 #define MAX_THICKRES 2    /* see eHairType */
 #define MAX_HAIR_SUBDIV 4 /* see hair_subdiv rna */
diff --git a/source/blender/draw/intern/draw_shader_shared.h b/source/blender/draw/intern/draw_shader_shared.h
index 23ded2ea5e9..3d0b3930121 100644
--- a/source/blender/draw/intern/draw_shader_shared.h
+++ b/source/blender/draw/intern/draw_shader_shared.h
@@ -27,7 +27,6 @@ typedef struct DRWDebugDrawBuffer DRWDebugDrawBuffer;
 /* C++ only forward declarations. */
 struct Object;
 struct ViewLayer;
-struct ID;
 struct GPUUniformAttr;
 struct GPULayerAttr;
 
diff --git a/source/blender/draw/intern/draw_subdivision.h b/source/blender/draw/intern/draw_subdivision.h
index 5133abc9257..a0e96ba4eeb 100644
--- a/source/blender/draw/intern/draw_subdivision.h
+++ b/source/blender/draw/intern/draw_subdivision.h
@@ -19,7 +19,6 @@ struct MeshBatchCache;
 struct MeshBufferCache;
 struct MeshRenderData;
 struct Object;
-struct Scene;
 struct Subdiv;
 struct ToolSettings;
 
diff --git a/source/blender/draw/intern/draw_view.h b/source/blender/draw/intern/draw_view.h
index d4a6f8a1a85..29825b11832 100644
--- a/source/blender/draw/intern/draw_view.h
+++ b/source/blender/draw/intern/draw_view.h
@@ -7,8 +7,6 @@
 
 #pragma once
 
-struct ARegion;
-
 void DRW_draw_region_info(void);
 void DRW_clear_background(void);
 void DRW_draw_cursor(void);
diff --git a/source/blender/editors/asset/ED_asset_handle.h b/source/blender/editors/asset/ED_asset_handle.h
index c11f94a3259..7bbba9b379e 100644
--- a/source/blender/editors/asset/ED_asset_handle.h
+++ b/source/blender/editors/asset/ED_asset_handle.h
@@ -19,8 +19,6 @@ extern "C" {
 #endif
 
 struct AssetHandle;
-struct AssetLibraryReference;
-struct bContext;
 
 const char *ED_asset_handle_get_name(const struct AssetHandle *asset);
 struct AssetMetaData *ED_asset_handle_get_metadata(const struct AssetHandle *asset);
diff --git a/source/blender/editors/asset/ED_asset_list.h b/source/blender/editors/asset/ED_asset_list.h
index 635dc3bff32..30f961421a5 100644
--- a/source/blender/editors/asset/ED_asset_list.h
+++ b/source/blender/editors/asset/ED_asset_list.h
@@ -10,7 +10,6 @@
 extern "C" {
 #endif
 
-struct AssetFilterSettings;
 struct AssetHandle;
 struct AssetLibraryReference;
 struct ID;
diff --git a/source/blender/editors/asset/ED_asset_list.hh b/source/blender/editors/asset/ED_asset_list.hh
index c99890974d5..524fee274f8 100644
--- a/source/blender/editors/asset/ED_asset_list.hh
+++ b/source/blender/editors/asset/ED_asset_list.hh
@@ -12,8 +12,6 @@
 
 struct AssetHandle;
 struct AssetLibraryReference;
-struct FileDirEntry;
-struct bContext;
 
 namespace blender::asset_system {
 class AssetLibrary;
diff --git a/source/blender/editors/asset/ED_asset_temp_id_consumer.h b/source/blender/editors/asset/ED_asset_temp_id_consumer.h
index d6ed2509a32..e166aecb13a 100644
--- a/source/blender/editors/asset/ED_asset_temp_id_consumer.h
+++ b/source/blender/editors/asset/ED_asset_temp_id_consumer.h
@@ -20,10 +20,8 @@ extern "C" {
 typedef struct AssetTempIDConsumer AssetTempIDConsumer;
 
 struct AssetHandle;
-struct AssetLibraryReference;
 struct Main;
 struct ReportList;
-struct bContext;
 
 AssetTempIDConsumer *ED_asset_temp_id_consumer_create(const struct AssetHandle *handle);
 void ED_asset_temp_id_consumer_free(AssetTempIDConsumer **consumer);
diff --git a/source/blender/editors/include/ED_armature.h b/source/blender/editors/include/ED_armature.h
index fb1c1912801..fcbaf9e115d 100644
--- a/source/blender/editors/include/ED_armature.h
+++ b/source/blender/editors/include/ED_armature.h
@@ -31,7 +31,6 @@ struct SelectPick_Params;
 struct UndoType;
 struct View3D;
 struct ViewLayer;
-struct bAction;
 struct bArmature;
 struct bContext;
 struct bPoseChannel;
diff --git a/source/blender/editors/include/ED_curves_sculpt.h b/source/blender/editors/include/ED_curves_sculpt.h
index 66f57670cec..8aab1533e25 100644
--- a/source/blender/editors/include/ED_curves_sculpt.h
+++ b/source/blender/editors/include/ED_curves_sculpt.h
@@ -10,8 +10,6 @@
 extern "C" {
 #endif
 
-struct Curves;
-
 void ED_operatortypes_sculpt_curves(void);
 
 #ifdef __cplusplus
diff --git a/source/blender/editors/include/ED_file_indexer.h b/source/blender/editors/include/ED_file_indexer.h
index eeb0fb3124f..981a6015a94 100644
--- a/source/blender/editors/include/ED_file_indexer.h
+++ b/source/blender/editors/include/ED_file_indexer.h
@@ -22,7 +22,6 @@ extern "C" {
  * `filelist_setindexer` function.
  */
 
-struct AssetLibraryReference;
 struct LinkNode;
 
 /**
diff --git a/source/blender/editors/include/ED_fileselect.h b/source/blender/editors/include/ED_fileselect.h
index 9d5d8dd54cb..d4470c017bd 100644
--- a/source/blender/editors/include/ED_fileselect.h
+++ b/source/blender/editors/include/ED_fileselect.h
@@ -17,7 +17,6 @@ struct ARegion;
 struct FileAssetSelectParams;
 struct FileDirEntry;
 struct FileSelectParams;
-struct Scene;
 struct ScrArea;
 struct SpaceFile;
 struct bContext;
diff --git a/source/blender/editors/include/ED_gizmo_library.h b/source/blender/editors/include/ED_gizmo_library.h
index 31c1f93f5bc..9d65e23415c 100644
--- a/source/blender/editors/include/ED_gizmo_library.h
+++ b/source/blender/editors/include/ED_gizmo_library.h
@@ -32,7 +32,6 @@ void ED_gizmotypes_snap_3d(void);
 struct Object;
 struct bContext;
 struct wmGizmo;
-struct wmWindowManager;
 
 /* -------------------------------------------------------------------- */
 /* Shape Presets
diff --git a/source/blender/editors/include/ED_keyframes_keylist.h b/source/blender/editors/include/ED_keyframes_keylist.h
index 251b6e4d83d..7aaeb41572b 100644
--- a/source/blender/editors/include/ED_keyframes_keylist.h
+++ b/source/blender/editors/include/ED_keyframes_keylist.h
@@ -15,7 +15,6 @@ extern "C" {
 
 struct AnimData;
 struct CacheFile;
-struct DLRBT_Tree;
 struct FCurve;
 struct MaskLayer;
 struct Object;
diff --git a/source/blender/editors/include/ED_node.h b/source/blender/editors/include/ED_node.h
index f996a9f4591..d6f2fb10fe2 100644
--- a/source/blender/editors/include/ED_node.h
+++ b/source/blender/editors/include/ED_node.h
@@ -14,13 +14,11 @@ extern "C" {
 struct ID;
 struct Main;
 struct Scene;
-struct ScrArea;
 struct SpaceNode;
 struct Tex;
 struct View2D;
 struct bContext;
 struct bNode;
-struct bNodeSocket;
 struct bNodeSocketType;
 struct bNodeTree;
 struct bNodeTreeType;
diff --git a/source/blender/editors/include/ED_node.hh b/source/blender/editors/include/ED_node.hh
index ff88eedb5a4..385430d3856 100644
--- a/source/blender/editors/include/ED_node.hh
+++ b/source/blender/editors/include/ED_node.hh
@@ -8,6 +8,7 @@
 struct SpaceNode;
 struct ARegion;
 struct Main;
+struct bNodeSocket;
 struct bNodeTree;
 struct rcti;
 
diff --git a/source/blender/editors/include/ED_object.h b/source/blender/editors/include/ED_object.h
index 9e8d9636a29..798175b7cb8 100644
--- a/source/blender/editors/include/ED_object.h
+++ b/source/blender/editors/include/ED_object.h
@@ -35,7 +35,6 @@ struct bContext;
 struct bFaceMap;
 struct bPoseChannel;
 struct uiLayout;
-struct wmEvent;
 struct wmKeyConfig;
 struct wmOperator;
 struct wmOperatorType;
diff --git a/source/blender/editors/include/ED_sculpt.h b/source/blender/editors/include/ED_sculpt.h
index bc4e3b88586..fca7476fcf3 100644
--- a/source/blender/editors/include/ED_sculpt.h
+++ b/source/blender/editors/include/ED_sculpt.h
@@ -17,9 +17,6 @@ struct UndoType;
 struct ViewContext;
 struct bContext;
 struct rcti;
-struct wmMsgSubscribeKey;
-struct wmMsgSubscribeValue;
-struct wmRegionMessageSubscribeParams;
 struct wmOperator;
 
 /* sculpt.cc */
diff --git a/source/blender/editors/include/ED_select_utils.h b/source/blender/editors/include/ED_select_utils.h
index 8c856794ec8..a3ac86ab041 100644
--- a/source/blender/editors/include/ED_select_utils.h
+++ b/source/blender/editors/include/ED_select_utils.h
@@ -13,7 +13,6 @@ extern "C" {
 #endif
 
 struct KDTree_1d;
-struct wmOperator;
 struct wmOperatorType;
 
 enum {
diff --git a/source/blender/editors/include/ED_spreadsheet.h b/source/blender/editors/include/ED_spreadsheet.h
index 736da367a44..924c8bdd611 100644
--- a/source/blender/editors/include/ED_spreadsheet.h
+++ b/source/blender/editors/include/ED_spreadsheet.h
@@ -3,12 +3,7 @@
 #pragma once
 
 struct ID;
-struct Main;
-struct Object;
-struct SpaceNode;
 struct SpaceSpreadsheet;
-struct bContext;
-struct bNode;
 
 #ifdef __cplusplus
 extern "C" {
diff --git a/source/blender/editors/include/ED_util.h b/source/blender/editors/include/ED_util.h
index 98a9746292b..42406f727ed 100644
--- a/source/blender/editors/include/ED_util.h
+++ b/source/blender/editors/include/ED_util.h
@@ -14,7 +14,6 @@
 extern "C" {
 #endif
 
-struct GPUBatch;
 struct IDRemapper;
 struct Main;
 struct bContext;
diff --git a/source/blender/editors/include/UI_abstract_view.hh b/source/blender/editors/include/UI_abstract_view.hh
index dfddace8899..e2f395ec203 100644
--- a/source/blender/editors/include/UI_abstract_view.hh
+++ b/source/blender/editors/include/UI_abstract_view.hh
@@ -27,7 +27,6 @@
 
 struct bContext;
 struct uiBlock;
-struct uiBut;
 struct uiLayout;
 struct uiViewItemHandle;
 struct wmDrag;
diff --git a/source/blender/editors/include/UI_grid_view.hh b/source/blender/editors/include/UI_grid_view.hh
index 402c0c8512f..6f3dfa1978b 100644
--- a/source/blender/editors/include/UI_grid_view.hh
+++ b/source/blender/editors/include/UI_grid_view.hh
@@ -17,12 +17,10 @@
 #include "UI_resources.h"
 
 struct bContext;
-struct PreviewImage;
 struct uiBlock;
 struct uiButViewItem;
 struct uiLayout;
 struct View2D;
-struct wmNotifier;
 
 namespace blender::ui {
 
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 0705052921e..cdc41ef2183 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -22,10 +22,8 @@ extern "C" {
 struct ARegion;
 struct AssetFilterSettings;
 struct AssetHandle;
-struct AssetMetaData;
 struct AutoComplete;
 struct EnumPropertyItem;
-struct FileDirEntry;
 struct FileSelectParams;
 struct ID;
 struct IDProperty;
@@ -48,7 +46,6 @@ struct bNodeTree;
 struct bScreen;
 struct rctf;
 struct rcti;
-struct uiBlockInteraction_Handle;
 struct uiButSearch;
 struct uiFontStyle;
 struct uiList;
diff --git a/source/blender/editors/interface/interface_handlers.cc b/source/blender/editors/interface/interface_handlers.cc
index 44a14f254c0..63e415b07aa 100644
--- a/source/blender/editors/interface/interface_handlers.cc
+++ b/source/blender/editors/interface/interface_handlers.cc
@@ -150,6 +150,8 @@
 /** \name Local Prototypes
  * \{ */
 
+struct uiBlockInteraction_Handle;
+
 static int ui_do_but_EXIT(bContext *C, uiBut *but, uiHandleButtonData *data, const wmEvent *event);
 static bool ui_but_find_select_in_enum__cmp(const uiBut *but_a, const uiBut *but_b);
 static void ui_textedit_string_set(uiBut *but, uiHandleButtonData *data, const char *str);
diff --git a/source/blender/editors/space_node/node_intern.hh b/source/blender/editors/space_node/node_intern.hh
index fe7af557f2f..f9804144fb0 100644
--- a/source/blender/editors/space_node/node_intern.hh
+++ b/source/blender/editors/space_node/node_intern.hh
@@ -19,8 +19,6 @@
 #include "UI_view2d.h"
 
 struct ARegion;
-struct ARegionType;
-struct Main;
 struct NodeInsertOfsData;
 struct View2D;
 struct bContext;
diff --git a/source/blender/editors/space_spreadsheet/spreadsheet_column_values.hh b/source/blender/editors/space_spreadsheet/spreadsheet_column_values.hh
index 7cf9238d34e..31902c11518 100644
--- a/source/blender/editors/space_spreadsheet/spreadsheet_column_values.hh
+++ b/source/blender/editors/space_spreadsheet/spreadsheet_column_values.hh
@@ -9,8 +9,6 @@
 
 namespace blender::ed::spreadsheet {
 
-struct CellDrawParams;
-
 eSpreadsheetColumnValueType cpp_type_to_column_type(const CPPType &type);
 
 /**
diff --git a/source/blender/editors/space_view3d/view3d_intern.h b/source/blender/editors/space_view3d/view3d_intern.h
index 08d42471998..bfc2cf5214a 100644
--- a/source/blender/editors/space_view3d/view3d_intern.h
+++ b/source/blender/editors/space_view3d/view3d_intern.h
@@ -28,7 +28,6 @@ struct wmGizmoGroupType;
 struct wmGizmoType;
 struct wmKeyConfig;
 struct wmOperatorType;
-struct wmWindowManager;
 
 /* view3d_header.c */
 
diff --git a/source/blender/editors/space_view3d/view3d_navigate.h b/source/blender/editors/space_view3d/view3d_navigate.h
index 7342b8cc7cb..46dacbc606f 100644
--- a/source/blender/editors/space_view3d/view3d_navigate.h
+++ b/source/blender/editors/space_view3d/view3d_navigate.h
@@ -28,7 +28,6 @@ struct View3D;
 struct bContext;
 struct rcti;
 struct wmEvent;
-struct wmOperator;
 
 enum eV3D_OpPropFlag {
   V3D_OP_PROP_MOUSE_CO = (1 << 0),
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 13362cee2b6..637e4ef3b6e 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -28,7 +28,6 @@ extern "C" {
  * \{ */
 
 struct ARegion;
-struct BMPartialUpdate;
 struct Depsgraph;
 struct NumInput;
 struct Object;
diff --git a/source/blender/editors/transform/transform_convert.h b/source/blender/editors/transform/transform_convert.h
index c3d2a1d86d9..dd1e305762d 100644
--- a/source/blender/editors/transform/transform_convert.h
+++ b/source/blender/editors/transform/transform_convert.h
@@ -17,7 +17,6 @@ extern "C" {
 struct BMEditMesh;
 struct BMesh;
 struct BezTriple;
-struct FCurve;
 struct ListBase;
 struct Object;
 struct TransData;
diff --git a/source/blender/editors/transform/transform_mode.h b/source/blender/editors/transform/transform_mode.h
index b782d27a3c6..6fc82a484bd 100644
--- a/source/blender/editors/transform/transform_mode.h
+++ b/source/blender/editors/transform/transform_mode.h
@@ -8,7 +8,6 @@
 
 #pragma once
 
-struct AnimData;
 struct LinkNode;
 struct TransData;
 struct TransDataContainer;
diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index 5a6db911ee5..3cf64edaa6e 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -11,7 +11,6 @@
 extern "C" {
 #endif
 
-struct GPUIndexBuf;
 struct GPUVertBuf;
 
 /** Opaque type hiding #blender::gpu::shader::ShaderCreateInfo */
diff --git a/source/blender/gpu/GPU_storage_buffer.h b/source/blender/gpu/GPU_storage_buffer.h
index 8837a7c7647..8ed60d9000a 100644
--- a/source/blender/gpu/GPU_storage_buffer.h
+++ b/source/blender/gpu/GPU_storage_buffer.h
@@ -20,8 +20,6 @@
 extern "C" {
 #endif
 
-struct ListBase;
-
 /** Opaque type hiding blender::gpu::StorageBuf. */
 typedef struct GPUStorageBuf GPUStorageBuf;
 
diff --git a/source/blender/gpu/GPU_viewport.h b/source/blender/gpu/GPU_viewport.h
index be989635f84..2f326c2f680 100644
--- a/source/blender/gpu/GPU_viewport.h
+++ b/source/blender/gpu/GPU_viewport.h
@@ -25,8 +25,6 @@ typedef struct GHash GHash;
 typedef struct GPUViewport GPUViewport;
 
 struct DRWData;
-struct DefaultFramebufferList;
-struct DefaultTextureList;
 struct GPUFrameBuffer;
 
 GPUViewport *GPU_viewport_create(void);
diff --git a/source/blender/imbuf/IMB_colormanagement.h b/source/blender/imbuf/IMB_colormanagement.h
index 2fb1d814c83..c60fc7d5563 100644
--- a/source/blender/imbuf/IMB_colormanagement.h
+++ b/source/blender/imbuf/IMB_colormanagement.h
@@ -19,7 +19,6 @@ extern "C" {
 struct ColorManagedColorspaceSettings;
 struct ColorManagedDisplaySettings;
 struct ColorManagedViewSettings;
-struct ColorManagedOutputSettings;
 struct ColormanageProcessor;
 struct EnumPropertyItem;
 struct ImBuf;
diff --git a/source/blender/io/usd/intern/usd_reader_prim.h b/source/blender/io/usd/intern/usd_reader_prim.h
index c44c4a14ad7..377228929ff 100644
--- a/source/blender/io/usd/intern/usd_reader_prim.h
+++ b/source/blender/io/usd/intern/usd_reader_prim.h
@@ -10,6 +10,7 @@
 #include <map>
 #include <string>
 
+struct CacheFile;
 struct Main;
 struct Material;
 struct Object;
diff --git a/source/blender/io/usd/intern/usd_writer_material.h b/source/blender/io/usd/intern/usd_writer_material.h
index 3e9b84477d5..fdfd13871ff 100644
--- a/source/blender/io/usd/intern/usd_writer_material.h
+++ b/source/blender/io/usd/intern/usd_writer_material.h
@@ -9,9 +9,6 @@
 #include <string>
 
 struct Material;
-struct USDExportParams;
-struct bNode;
-struct bNodeTree;
 
 namespace blender::io::usd {
 
diff --git a/source/blender/io/usd/usd.h b/source/blender/io/usd/usd.h
index 98979eb9c13..9d5cda64424 100644
--- a/source/blender/io/usd/usd.h
+++ b/source/blender/io/usd/usd.h
@@ -10,7 +10,6 @@ extern "C" {
 #endif
 
 struct CacheArchiveHandle;
-struct CacheFile;
 struct CacheReader;
 struct Object;
 struct bContext;
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index c0ea55885d0..6e39ad0d4f7 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -53,10 +53,8 @@ struct bGPdata;
 struct bNodeInstanceHash;
 struct bNodeLink;
 struct bNodePreview;
-struct bNodeTreeExec;
 struct bNodeType;
 struct bNode;
-struct uiBlock;
 
 #define NODE_MAXSTR 64
 
diff --git a/source/blender/makesdna/DNA_view3d_types.h b/source/blender/makesdna/DNA_view3d_types.h
index 0b7c483b7d0..4c5ba4c43f8 100644
--- a/source/blender/makesdna/DNA_view3d_types.h
+++ b/source/blender/makesdna/DNA_view3d_types.h
@@ -12,7 +12,6 @@ struct Object;
 struct RenderEngine;
 struct SmoothView3DStore;
 struct SpaceLink;
-struct ViewDepths;
 struct bGPdata;
 struct wmTimer;
 
diff --git a/source/blender/makesdna/DNA_windowmanager_types.h b/source/blender/makesdna/DNA_windowmanager_types.h
index 6e5bb593d22..3c2fd5af543 100644
--- a/source/blender/makesdna/DNA_windowmanager_types.h
+++ b/source/blender/makesdna/DNA_windowmanager_types.h
@@ -23,7 +23,6 @@ struct wmWindow;
 struct wmWindowManager;
 
 struct wmEvent;
-struct wmGesture;
 struct wmKeyConfig;
 struct wmKeyMap;
 struct wmMsgBus;
diff --git a/source/blender/makesrna/intern/rna_internal.h b/source/blender/makesrna/intern/rna_internal.h
index 57aea23024f..b39bc6de7e5 100644
--- a/source/blender/makesrna/intern/rna_internal.h
+++ b/source/blender/makesrna/intern/rna_internal.h
@@ -20,11 +20,9 @@ extern "C" {
 
 #define RNA_MAGIC ((int)~0)
 
-struct AssetLibraryReference;
 struct FreestyleSettings;
 struct ID;
 struct IDOverrideLibrary;
-struct IDOverrideLibraryenOperation;
 struct IDProperty;
 struct Main;
 struct Object;
diff --git a/source/blender/modifiers/MOD_nodes.h b/source/blender/modifiers/MOD_nodes.h
index 4a3ccd8ecd1..b3c353e2347 100644
--- a/source/blender/modifiers/MOD_nodes.h
+++ b/source/blender/modifiers/MOD_nodes.h
@@ -2,7 +2,6 @@
 
 #pragma once
 
-struct Main;
 struct NodesModifierData;
 struct Object;
 
diff --git a/source/blender/nodes/NOD_geometry_exec.hh b/source/blender/nodes/NOD_geometry_exec.hh
index 088e076be35..208d51f13d3 100644
--- a/source/blender/nodes/NOD_geometry_exec.hh
+++ b/source/blender/nodes/NOD_geometry_exec.hh
@@ -14,8 +14,6 @@
 #include "NOD_derived_node_tree.hh"
 #include "NOD_geometry_nodes_lazy_function.hh"
 
-struct ModifierData;
-
 namespace blender::nodes {
 
 using bke::AnonymousAttributeFieldInput;
diff --git a/source/blender/nodes/NOD_geometry_nodes_log.hh b/source/blender/nodes/NOD_geometry_nodes_log.hh
index 95e54f1b9a5..3d453de4b78 100644
--- a/source/blender/nodes/NOD_geometry_nodes_log.hh
+++ b/source/blender/nodes/NOD_geometry_nodes_log.hh
@@ -40,8 +40,6 @@
 #include "DNA_node_types.h"
 
 struct SpaceNode;
-struct SpaceSpreadsheet;
-struct NodesModifierData;
 
 namespace blender::nodes::geo_eval_log {
 
diff --git a/source/blender/python/generic/idprop_py_ui_api.h b/source/blender/python/generic/idprop_py_ui_api.h
index e3017c9ad0a..2a14960cd79 100644
--- a/source/blender/python/generic/idprop_py_ui_api.h
+++ b/source/blender/python/generic/idprop_py_ui_api.h
@@ -6,7 +6,6 @@
 
 #pragma once
 
-struct ID;
 struct IDProperty;
 
 extern PyTypeObject BPy_IDPropertyUIManager_Type;
diff --git a/source/blender/python/gpu/gpu_py_offscreen.h b/source/blender/python/gpu/gpu_py_offscreen.h
index b9fbc6aab3c..f8b49ac15a5 100644
--- a/source/blender/python/gpu/gpu_py_offscreen.h
+++ b/source/blender/python/gpu/gpu_py_offscreen.h
@@ -12,7 +12,6 @@ extern PyTypeObject BPyGPUOffScreen_Type;
 
 #define BPyGPUOffScreen_Check(v) (Py_TYPE(v) == &BPyGPUOffScreen_Type)
 
-struct GPUOffscreen;
 struct GPUViewport;
 
 typedef struct BPyGPUOffScreen {
diff --git a/source/blender/python/intern/bpy_capi_utils.h b/source/blender/python/intern/bpy_capi_utils.h
index 73a5d2ebc79..7e24446eae5 100644
--- a/source/blender/python/intern/bpy_capi_utils.h
+++ b/source/blender/python/intern/bpy_capi_utils.h
@@ -14,7 +14,6 @@
 extern "C" {
 #endif
 
-struct EnumPropertyItem;
 struct ReportList;
 
 /* error reporting */
diff --git a/source/blender/render/RE_texture_margin.h b/source/blender/render/RE_texture_margin.h
index fd8e41adb3a..62d3782c85e 100644
--- a/source/blender/render/RE_texture_margin.h
+++ b/source/blender/render/RE_texture_margin.h
@@ -11,7 +11,6 @@ extern "C" {
 #endif
 
 struct DerivedMesh;
-struct IMBuf;
 struct ImBuf;
 struct Mesh;
 
diff --git a/source/blender/render/intern/pipeline.h b/source/blender/render/intern/pipeline.h
index e5da3cb8830..8ee29096dd1 100644
--- a/source/blender/render/intern/pipeline.h
+++ b/source/blender/render/intern/pipeline.h
@@ -7,7 +7,6 @@
 
 #pragma once
 
-struct ListBase;
 struct Render;
 struct RenderData;
 struct RenderLayer;
diff --git a/source/blender/render/intern/render_result.h b/source/blender/render/intern/render_result.h
index 6e971d45d31..6075dd3d396 100644
--- a/source/blender/render/intern/render_result.h
+++ b/source/blender/render/intern/render_result.h
@@ -18,10 +18,8 @@ struct ImBuf;
 struct ListBase;
 struct Render;
 struct RenderData;
-struct RenderEngine;
 struct RenderLayer;
 struct RenderResult;
-struct Scene;
 struct rcti;
 
 #ifdef __cplusplus
diff --git a/source/blender/sequencer/SEQ_channels.h b/source/blender/sequencer/SEQ_channels.h
index 197ad5e55de..83d055ab59c 100644
--- a/source/blender/sequencer/SEQ_channels.h
+++ b/source/blender/sequencer/SEQ_channels.h
@@ -13,7 +13,6 @@ extern "C" {
 
 struct Editing;
 struct ListBase;
-struct Scene;
 struct SeqTimelineChannel;
 struct Sequence;
 
diff --git a/source/blender/sequencer/SEQ_iterator.h b/source/blender/sequencer/SEQ_iterator.h
index e5adb2a33b1..76475f4b964 100644
--- a/source/blender/sequencer/SEQ_iterator.h
+++ b/source/blender/sequencer/SEQ_iterator.h
@@ -13,7 +13,6 @@ extern "C" {
 
 #include "BLI_ghash.h"
 
-struct Editing;
 struct GSet;
 struct GSetIterator;
 struct Sequence;
diff --git a/source/blender/sequencer/SEQ_sequencer.h b/source/blender/sequencer/SEQ_sequencer.h
index a77ca1c7baf..c795e6a684e 100644
--- a/source/blender/sequencer/SEQ_sequencer.h
+++ b/source/blender/sequencer/SEQ_sequencer.h
@@ -21,7 +21,6 @@ struct Depsgraph;
 struct Editing;
 struct Scene;
 struct Sequence;
-struct SequenceLookup;
 struct SequencerToolSettings;
 
 /* RNA enums, just to be more readable */
diff --git a/source/blender/sequencer/SEQ_transform.h b/source/blender/sequencer/SEQ_transform.h
index 30cf472f55b..28202dd252a 100644
--- a/source/blender/sequencer/SEQ_transform.h
+++ b/source/blender/sequencer/SEQ_transform.h
@@ -11,7 +11,6 @@
 extern "C" {
 #endif
 
-struct Editing;
 struct ListBase;
 struct Scene;
 struct SeqCollection;
diff --git a/source/blender/sequencer/SEQ_utils.h b/source/blender/sequencer/SEQ_utils.h
index 24ca7559166..f1679012ef3 100644
--- a/source/blender/sequencer/SEQ_utils.h
+++ b/source/blender/sequencer/SEQ_utils.h
@@ -16,7 +16,6 @@ extern "C" {
 struct ListBase;
 struct Mask;
 struct Scene;
-struct SeqRenderData;
 struct Sequence;
 struct StripElem;
 
diff --git a/source/blender/sequencer/intern/effects.h b/source/blender/sequencer/intern/effects.h
index c15701a2047..5ec6cb9eb19 100644
--- a/source/blender/sequencer/intern/effects.h
+++ b/source/blender/sequencer/intern/effects.h
@@ -12,7 +12,6 @@ extern "C" {
 #endif
 
 struct Scene;
-struct SeqRenderData;
 struct Sequence;
 
 struct SeqEffectHandle seq_effect_get_sequence_blend(struct Sequence *seq);
diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index 37dce4db61d..ee0cba5ec7c 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -26,7 +26,6 @@ extern "C" {
 
 struct ARegion;
 struct AssetHandle;
-struct AssetLibraryReference;
 struct GHashIterator;
 struct GPUViewport;
 struct ID;
@@ -39,7 +38,6 @@ struct MenuType;
 struct PointerRNA;
 struct PropertyRNA;
 struct ScrArea;
-struct SelectPick_Params;
 struct View3D;
 struct ViewLayer;
 struct bContext;