diff --git a/ChangeLog b/ChangeLog
index c4ce83c06a..1b07be16ad 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat May 23 18:48:52 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/dl/cptr.c (rb_dlptr_cmp): return signed value, and restric
+	  to Fixnum.  [ruby-dev:38533]
+
 Fri May 22 23:22:53 2009  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* missing/vsnprintf.c (errno): [BUG] fixes a compilation 
diff --git a/ext/dl/cptr.c b/ext/dl/cptr.c
index d2fa07771d..b7c27e9f9e 100644
--- a/ext/dl/cptr.c
+++ b/ext/dl/cptr.c
@@ -318,9 +318,12 @@ VALUE
 rb_dlptr_cmp(VALUE self, VALUE other)
 {
     void *ptr1, *ptr2;
+    SIGNED_VALUE diff;
     ptr1 = rb_dlptr2cptr(self);
     ptr2 = rb_dlptr2cptr(other);
-    return PTR2NUM((long)ptr1 - (long)ptr2);
+    diff = (SIGNED_VALUE)ptr1 - (SIGNED_VALUE)ptr2;
+    if (!diff) return INT2FIX(0);
+    return diff > 0 ? INT2NUM(1) : INT2NUM(-1);
 }
 
 VALUE