diff --git a/src/gc.c b/src/gc.c
index c4bb77e3a..583fde413 100644
--- a/src/gc.c
+++ b/src/gc.c
@@ -1004,8 +1004,8 @@ gc_disable(mrb_state *mrb, mrb_value obj)
   int old = mrb->gc_disabled;
 
   mrb->gc_disabled = TRUE;
-  if (old) return mrb_true_value();
-  return mrb_false_value();
+
+  return mrb_true_or_false_value(old);
 }
 
 /*