diff --git a/gc.c b/gc.c
index 5793d64124..b485a3ba39 100644
--- a/gc.c
+++ b/gc.c
@@ -6745,13 +6745,6 @@ rb_during_gc(void)
     return during_gc;
 }
 
-int
-rb_threadptr_during_gc(rb_thread_t *th)
-{
-    rb_objspace_t *objspace = rb_objspace_of(th->vm);
-    return during_gc;
-}
-
 #if RGENGC_PROFILE >= 2
 
 static const char *type_name(int type, VALUE obj);
diff --git a/gc.h b/gc.h
index b72ceda134..2c91e06620 100644
--- a/gc.h
+++ b/gc.h
@@ -91,7 +91,6 @@ const char *rb_raw_obj_info(char *buff, const int buff_size, VALUE obj);
 void rb_obj_info_dump(VALUE obj);
 
 struct rb_thread_struct;
-int rb_threadptr_during_gc(struct rb_thread_struct *th);
 
 RUBY_SYMBOL_EXPORT_BEGIN