diff --git a/source/blender/blenkernel/BKE_layer.h b/source/blender/blenkernel/BKE_layer.h
index b903545bd3b..024d58174e8 100644
--- a/source/blender/blenkernel/BKE_layer.h
+++ b/source/blender/blenkernel/BKE_layer.h
@@ -99,7 +99,7 @@ void BKE_main_collection_sync(const struct Main *bmain);
 void BKE_scene_collection_sync(const struct Scene *scene);
 void BKE_layer_collection_sync(const struct Scene *scene, struct ViewLayer *view_layer);
 void BKE_layer_collection_local_sync(struct ViewLayer *view_layer, const struct View3D *v3d);
-void BKE_layer_collection_local_sync_all(struct Main *bmain);
+void BKE_layer_collection_local_sync_all(const struct Main *bmain);
 
 void BKE_main_collection_sync_remap(const struct Main *bmain);
 
diff --git a/source/blender/blenkernel/intern/layer.c b/source/blender/blenkernel/intern/layer.c
index 2f1ad2559f9..05ab03d75a2 100644
--- a/source/blender/blenkernel/intern/layer.c
+++ b/source/blender/blenkernel/intern/layer.c
@@ -1250,7 +1250,7 @@ void BKE_layer_collection_local_sync(ViewLayer *view_layer, const View3D *v3d)
 /**
  * Sync the local collection for all the viewports.
  */
-void BKE_layer_collection_local_sync_all(Main *bmain)
+void BKE_layer_collection_local_sync_all(const Main *bmain)
 {
   LISTBASE_FOREACH (Scene *, scene, &bmain->scenes) {
     LISTBASE_FOREACH (ViewLayer *, view_layer, &scene->view_layers) {