diff --git a/source/blender/blenkernel/BKE_main_idmap.h b/source/blender/blenkernel/BKE_main_idmap.hh
similarity index 51%
rename from source/blender/blenkernel/BKE_main_idmap.h
rename to source/blender/blenkernel/BKE_main_idmap.hh
index 25f38dfd71d..92d4a167efb 100644
--- a/source/blender/blenkernel/BKE_main_idmap.h
+++ b/source/blender/blenkernel/BKE_main_idmap.hh
@@ -19,10 +19,6 @@
 
 #include "BLI_compiler_attrs.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 struct ID;
 struct IDNameLib_Map;
 struct Main;
@@ -43,31 +39,23 @@ enum {
  * \param create_valid_ids_set: If \a true, generate a reference to prevent freed memory accesses.
  * \param old_bmain: If not NULL, its IDs will be added the valid references set.
  */
-struct IDNameLib_Map *BKE_main_idmap_create(struct Main *bmain,
-                                            bool create_valid_ids_set,
-                                            struct Main *old_bmain,
-                                            int idmap_types) ATTR_WARN_UNUSED_RESULT
-    ATTR_NONNULL(1);
-void BKE_main_idmap_destroy(struct IDNameLib_Map *id_map) ATTR_NONNULL();
+IDNameLib_Map *BKE_main_idmap_create(Main *bmain,
+                                     bool create_valid_ids_set,
+                                     Main *old_bmain,
+                                     int idmap_types) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
+void BKE_main_idmap_destroy(IDNameLib_Map *id_map) ATTR_NONNULL();
 
-void BKE_main_idmap_insert_id(struct IDNameLib_Map *id_map, struct ID *id) ATTR_NONNULL();
-void BKE_main_idmap_remove_id(struct IDNameLib_Map *id_map, struct ID *id) ATTR_NONNULL();
+void BKE_main_idmap_insert_id(IDNameLib_Map *id_map, ID *id) ATTR_NONNULL();
+void BKE_main_idmap_remove_id(IDNameLib_Map *id_map, ID *id) ATTR_NONNULL();
 
-struct Main *BKE_main_idmap_main_get(struct IDNameLib_Map *id_map) ATTR_WARN_UNUSED_RESULT
-    ATTR_NONNULL();
+Main *BKE_main_idmap_main_get(IDNameLib_Map *id_map) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 
-struct ID *BKE_main_idmap_lookup_name(struct IDNameLib_Map *id_map,
-                                      short id_type,
-                                      const char *name,
-                                      const struct Library *lib) ATTR_WARN_UNUSED_RESULT
-    ATTR_NONNULL(1, 3);
-struct ID *BKE_main_idmap_lookup_id(struct IDNameLib_Map *id_map,
-                                    const struct ID *id) ATTR_WARN_UNUSED_RESULT
+ID *BKE_main_idmap_lookup_name(IDNameLib_Map *id_map,
+                               short id_type,
+                               const char *name,
+                               const Library *lib) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1, 3);
+ID *BKE_main_idmap_lookup_id(IDNameLib_Map *id_map, const ID *id) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL(1, 2);
 
-struct ID *BKE_main_idmap_lookup_uuid(struct IDNameLib_Map *id_map,
-                                      uint session_uuid) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL(1);
-
-#ifdef __cplusplus
-}
-#endif
+ID *BKE_main_idmap_lookup_uuid(IDNameLib_Map *id_map, uint session_uuid) ATTR_WARN_UNUSED_RESULT
+    ATTR_NONNULL(1);
diff --git a/source/blender/blenkernel/BKE_main_namemap.h b/source/blender/blenkernel/BKE_main_namemap.hh
similarity index 71%
rename from source/blender/blenkernel/BKE_main_namemap.h
rename to source/blender/blenkernel/BKE_main_namemap.hh
index 3f08189a902..928a6132b4c 100644
--- a/source/blender/blenkernel/BKE_main_namemap.h
+++ b/source/blender/blenkernel/BKE_main_namemap.hh
@@ -20,16 +20,12 @@
 
 #include "BLI_compiler_attrs.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 struct ID;
 struct Main;
 struct UniqueName_Map;
 
-struct UniqueName_Map *BKE_main_namemap_create(void) ATTR_WARN_UNUSED_RESULT;
-void BKE_main_namemap_destroy(struct UniqueName_Map **r_name_map) ATTR_NONNULL();
+UniqueName_Map *BKE_main_namemap_create(void) ATTR_WARN_UNUSED_RESULT;
+void BKE_main_namemap_destroy(UniqueName_Map **r_name_map) ATTR_NONNULL();
 
 /**
  * Destroy all name_maps in given bmain:
@@ -38,7 +34,7 @@ void BKE_main_namemap_destroy(struct UniqueName_Map **r_name_map) ATTR_NONNULL()
  *   readfile code).
  * - In all of the libraries IDs (for linked IDs).
  */
-void BKE_main_namemap_clear(struct Main *bmain) ATTR_NONNULL();
+void BKE_main_namemap_clear(Main *bmain) ATTR_NONNULL();
 
 /**
  * Ensures the given name is unique within the given ID type.
@@ -50,18 +46,15 @@ void BKE_main_namemap_clear(struct Main *bmain) ATTR_NONNULL();
  *
  * \return true if the name had to be adjusted for uniqueness.
  */
-bool BKE_main_namemap_get_name(struct Main *bmain,
-                               struct ID *id,
-                               char *name,
-                               const bool do_unique_in_bmain) ATTR_NONNULL();
+bool BKE_main_namemap_get_name(Main *bmain, ID *id, char *name, const bool do_unique_in_bmain)
+    ATTR_NONNULL();
 
 /**
  * Remove a given name from usage.
  *
  * Call this whenever deleting or renaming an object.
  */
-void BKE_main_namemap_remove_name(struct Main *bmain, struct ID *id, const char *name)
-    ATTR_NONNULL();
+void BKE_main_namemap_remove_name(Main *bmain, ID *id, const char *name) ATTR_NONNULL();
 
 /**
  * Check that all ID names in given `bmain` are unique (per ID type and library), and that existing
@@ -69,7 +62,7 @@ void BKE_main_namemap_remove_name(struct Main *bmain, struct ID *id, const char
  *
  * This is typically called within an assert, or in tests.
  */
-bool BKE_main_namemap_validate(struct Main *bmain) ATTR_NONNULL();
+bool BKE_main_namemap_validate(Main *bmain) ATTR_NONNULL();
 
 /**
  * Same as #BKE_main_namemap_validate, but also fixes any issue by re-generating all name maps,
@@ -77,8 +70,4 @@ bool BKE_main_namemap_validate(struct Main *bmain) ATTR_NONNULL();
  *
  * This is typically only used in `do_versions` code to fix broken files.
  */
-bool BKE_main_namemap_validate_and_fix(struct Main *bmain) ATTR_NONNULL();
-
-#ifdef __cplusplus
-}
-#endif
+bool BKE_main_namemap_validate_and_fix(Main *bmain) ATTR_NONNULL();
diff --git a/source/blender/blenkernel/CMakeLists.txt b/source/blender/blenkernel/CMakeLists.txt
index b7ffd4970d6..2debd261c5f 100644
--- a/source/blender/blenkernel/CMakeLists.txt
+++ b/source/blender/blenkernel/CMakeLists.txt
@@ -424,8 +424,8 @@ set(SRC
   BKE_lightprobe.h
   BKE_linestyle.h
   BKE_main.h
-  BKE_main_idmap.h
-  BKE_main_namemap.h
+  BKE_main_idmap.hh
+  BKE_main_namemap.hh
   BKE_mask.h
   BKE_material.h
   BKE_mball.h
diff --git a/source/blender/blenkernel/intern/blendfile.cc b/source/blender/blenkernel/intern/blendfile.cc
index e4d734cf6cd..5cb937a1511 100644
--- a/source/blender/blenkernel/intern/blendfile.cc
+++ b/source/blender/blenkernel/intern/blendfile.cc
@@ -48,8 +48,8 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_idmap.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_idmap.hh"
+#include "BKE_main_namemap.hh"
 #include "BKE_preferences.h"
 #include "BKE_report.h"
 #include "BKE_scene.h"
diff --git a/source/blender/blenkernel/intern/blendfile_link_append.cc b/source/blender/blenkernel/intern/blendfile_link_append.cc
index 883bb502b4d..588caa17474 100644
--- a/source/blender/blenkernel/intern/blendfile_link_append.cc
+++ b/source/blender/blenkernel/intern/blendfile_link_append.cc
@@ -43,7 +43,7 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_material.h"
 #include "BKE_object.hh"
 #include "BKE_report.h"
diff --git a/source/blender/blenkernel/intern/lib_id.cc b/source/blender/blenkernel/intern/lib_id.cc
index 88c17d1422b..e80926ad174 100644
--- a/source/blender/blenkernel/intern/lib_id.cc
+++ b/source/blender/blenkernel/intern/lib_id.cc
@@ -54,7 +54,7 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_node.h"
 #include "BKE_rigidbody.h"
 
diff --git a/source/blender/blenkernel/intern/lib_id_delete.cc b/source/blender/blenkernel/intern/lib_id_delete.cc
index 227c21dbba7..dac7b281ad5 100644
--- a/source/blender/blenkernel/intern/lib_id_delete.cc
+++ b/source/blender/blenkernel/intern/lib_id_delete.cc
@@ -31,7 +31,7 @@
 #include "BKE_lib_override.hh"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 
 #include "lib_intern.h"
 
diff --git a/source/blender/blenkernel/intern/lib_id_test.cc b/source/blender/blenkernel/intern/lib_id_test.cc
index 9e2bc583123..bc1d05b1601 100644
--- a/source/blender/blenkernel/intern/lib_id_test.cc
+++ b/source/blender/blenkernel/intern/lib_id_test.cc
@@ -11,7 +11,7 @@
 #include "BKE_idtype.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 
 #include "DNA_ID.h"
 #include "DNA_mesh_types.h"
diff --git a/source/blender/blenkernel/intern/lib_override.cc b/source/blender/blenkernel/intern/lib_override.cc
index f8dfe4a919f..4bf4afe2dd6 100644
--- a/source/blender/blenkernel/intern/lib_override.cc
+++ b/source/blender/blenkernel/intern/lib_override.cc
@@ -39,7 +39,7 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_node.hh"
 #include "BKE_report.h"
 #include "BKE_scene.h"
diff --git a/source/blender/blenkernel/intern/library.cc b/source/blender/blenkernel/intern/library.cc
index b05fac13f7b..dab004989df 100644
--- a/source/blender/blenkernel/intern/library.cc
+++ b/source/blender/blenkernel/intern/library.cc
@@ -27,7 +27,7 @@
 #include "BKE_lib_query.h"
 #include "BKE_library.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_packedFile.h"
 
 /* Unused currently. */
diff --git a/source/blender/blenkernel/intern/main.cc b/source/blender/blenkernel/intern/main.cc
index abda4f4dbe7..4d139b22869 100644
--- a/source/blender/blenkernel/intern/main.cc
+++ b/source/blender/blenkernel/intern/main.cc
@@ -24,8 +24,8 @@
 #include "BKE_lib_id.h"
 #include "BKE_lib_query.h"
 #include "BKE_main.h"
-#include "BKE_main_idmap.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_idmap.hh"
+#include "BKE_main_namemap.hh"
 
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
diff --git a/source/blender/blenkernel/intern/main_idmap.cc b/source/blender/blenkernel/intern/main_idmap.cc
index 80d61adcd5e..c43da90f72b 100644
--- a/source/blender/blenkernel/intern/main_idmap.cc
+++ b/source/blender/blenkernel/intern/main_idmap.cc
@@ -17,7 +17,7 @@
 #include "BKE_idtype.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
-#include "BKE_main_idmap.h" /* own include */
+#include "BKE_main_idmap.hh" /* own include */
 
 /** \file
  * \ingroup bke
diff --git a/source/blender/blenkernel/intern/main_namemap.cc b/source/blender/blenkernel/intern/main_namemap.cc
index 6391771f5a3..dc1f42cac77 100644
--- a/source/blender/blenkernel/intern/main_namemap.cc
+++ b/source/blender/blenkernel/intern/main_namemap.cc
@@ -9,7 +9,7 @@
 #include "BKE_idtype.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 
 #include "BLI_assert.h"
 #include "BLI_bitmap.h"
diff --git a/source/blender/blenloader/intern/readfile.cc b/source/blender/blenloader/intern/readfile.cc
index ea37e0b73a1..57204fa3c30 100644
--- a/source/blender/blenloader/intern/readfile.cc
+++ b/source/blender/blenloader/intern/readfile.cc
@@ -75,8 +75,8 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h" /* for Main */
-#include "BKE_main_idmap.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_idmap.hh"
+#include "BKE_main_namemap.hh"
 #include "BKE_material.h"
 #include "BKE_mesh.hh"
 #include "BKE_modifier.hh"
diff --git a/source/blender/blenloader/intern/versioning_300.cc b/source/blender/blenloader/intern/versioning_300.cc
index 1a9623124d6..b64e8d8d269 100644
--- a/source/blender/blenloader/intern/versioning_300.cc
+++ b/source/blender/blenloader/intern/versioning_300.cc
@@ -72,7 +72,7 @@
 #include "BKE_lib_id.h"
 #include "BKE_lib_override.hh"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_mesh.hh"
 #include "BKE_modifier.hh"
 #include "BKE_nla.h"
diff --git a/source/blender/blenloader/intern/versioning_common.cc b/source/blender/blenloader/intern/versioning_common.cc
index 3c7375d0a57..bd53f926325 100644
--- a/source/blender/blenloader/intern/versioning_common.cc
+++ b/source/blender/blenloader/intern/versioning_common.cc
@@ -24,7 +24,7 @@
 #include "BKE_lib_id.h"
 #include "BKE_lib_override.hh"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_mesh_legacy_convert.hh"
 #include "BKE_node.hh"
 #include "BKE_node_runtime.hh"
diff --git a/source/blender/blenloader/intern/versioning_defaults.cc b/source/blender/blenloader/intern/versioning_defaults.cc
index 94507fd7bd3..103973c0960 100644
--- a/source/blender/blenloader/intern/versioning_defaults.cc
+++ b/source/blender/blenloader/intern/versioning_defaults.cc
@@ -53,7 +53,7 @@
 #include "BKE_layer.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_material.h"
 #include "BKE_mesh.hh"
 #include "BKE_node.hh"
diff --git a/source/blender/blenloader/intern/writefile.cc b/source/blender/blenloader/intern/writefile.cc
index cb54da01cb7..d5064e45510 100644
--- a/source/blender/blenloader/intern/writefile.cc
+++ b/source/blender/blenloader/intern/writefile.cc
@@ -109,7 +109,7 @@
 #include "BKE_lib_override.hh"
 #include "BKE_lib_query.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_node.hh"
 #include "BKE_packedFile.h"
 #include "BKE_report.h"
diff --git a/source/blender/editors/space_file/filelist.cc b/source/blender/editors/space_file/filelist.cc
index 1261c29a7e0..45380b48a89 100644
--- a/source/blender/editors/space_file/filelist.cc
+++ b/source/blender/editors/space_file/filelist.cc
@@ -56,7 +56,7 @@
 #include "BKE_idtype.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
-#include "BKE_main_idmap.h"
+#include "BKE_main_idmap.hh"
 #include "BKE_preferences.h"
 #include "BKE_preview_image.hh"
 
diff --git a/source/blender/editors/space_outliner/outliner_draw.cc b/source/blender/editors/space_outliner/outliner_draw.cc
index 4d997fc46ea..545fc1f4ce8 100644
--- a/source/blender/editors/space_outliner/outliner_draw.cc
+++ b/source/blender/editors/space_outliner/outliner_draw.cc
@@ -38,7 +38,7 @@
 #include "BKE_lib_override.hh"
 #include "BKE_library.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_modifier.hh"
 #include "BKE_node.hh"
 #include "BKE_object.hh"
diff --git a/source/blender/makesrna/intern/rna_ID.cc b/source/blender/makesrna/intern/rna_ID.cc
index 37006169278..93d22b61dba 100644
--- a/source/blender/makesrna/intern/rna_ID.cc
+++ b/source/blender/makesrna/intern/rna_ID.cc
@@ -18,7 +18,7 @@
 
 #include "BKE_icons.h"
 #include "BKE_lib_id.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_object.hh"
 
 #include "RNA_access.hh"
diff --git a/source/blender/windowmanager/intern/wm_files.cc b/source/blender/windowmanager/intern/wm_files.cc
index bc7d176d8b3..404a56910ae 100644
--- a/source/blender/windowmanager/intern/wm_files.cc
+++ b/source/blender/windowmanager/intern/wm_files.cc
@@ -75,7 +75,7 @@
 #include "BKE_lib_override.hh"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
-#include "BKE_main_namemap.h"
+#include "BKE_main_namemap.hh"
 #include "BKE_packedFile.h"
 #include "BKE_report.h"
 #include "BKE_scene.h"