diff --git a/ChangeLog b/ChangeLog
index d4118fdacf..5dc4a1197b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jul 21 12:45:31 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* gc.c (rb_gc_enable, rb_gc_disable): should return Qtrue/Qfalse.
+
 Tue Jul 21 12:38:07 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* variable.c (rb_generic_ivar_memsize): should not remove generic
diff --git a/gc.c b/gc.c
index ef0804df71..18a32c8b7d 100644
--- a/gc.c
+++ b/gc.c
@@ -789,7 +789,7 @@ rb_gc_enable(void)
     int old = dont_gc;
 
     dont_gc = FALSE;
-    return old;
+    return old ? Qtrue : Qfalse;
 }
 
 /*
@@ -811,7 +811,7 @@ rb_gc_disable(void)
     int old = dont_gc;
 
     dont_gc = TRUE;
-    return old;
+    return old ? Qtrue : Qfalse;
 }
 
 VALUE rb_mGC;