diff --git a/src/include/utils/resowner.h b/src/include/utils/resowner.h
index c6a8c9743..c83cb90c2 100644
--- a/src/include/utils/resowner.h
+++ b/src/include/utils/resowner.h
@@ -65,7 +65,7 @@ extern void ResourceOwnerDelete(ResourceOwner owner);
 extern ResourceOwner ResourceOwnerGetParent(ResourceOwner owner);
 extern void ResourceOwnerNewParent(ResourceOwner owner, ResourceOwner newparent);
 extern void RegisterResourceReleaseCallback(ResourceReleaseCallback callback, void* arg);
-extern void UnregisterResourceReleaseCallback(ResourceReleaseCallback callback, void* arg);
+extern void UnregisterResourceReleaseCallback(ResourceReleaseCallback callback, const void* arg);
 
 /* support for buffer refcount management */
 extern void ResourceOwnerEnlargeBuffers(ResourceOwner owner);