2 files changed, 1 insertions, 2 deletions
diff --git a/gc.c b/gc.c
index 68df409602..a54cf52c17 100644
--- a/gc.c
+++ b/gc.c
@@ -3030,7 +3030,7 @@ rb_data_typed_object_zalloc(VALUE klass, size_t size, const rb_data_type_t *type
     return obj;
 }
 
-size_t
+static size_t
 rb_objspace_data_type_memsize(VALUE obj)
 {
     size_t size = 0;
diff --git a/internal/gc.h b/internal/gc.h
index a74ad52782..df5e4d8a3b 100644
--- a/internal/gc.h
+++ b/internal/gc.h
@@ -260,7 +260,6 @@ void rb_gc_ref_update_table_values_only(st_table *tbl);
 
 RUBY_SYMBOL_EXPORT_BEGIN
 /* exports for objspace module */
-size_t rb_objspace_data_type_memsize(VALUE obj);
 void rb_objspace_reachable_objects_from(VALUE obj, void (func)(VALUE, void *), void *data);
 void rb_objspace_reachable_objects_from_root(void (func)(const char *category, VALUE, void *), void *data);
 int rb_objspace_markable_object_p(VALUE obj);