diff --git a/ChangeLog b/ChangeLog
index a4150cf4c2..b0663d5797 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Dec 20 10:20:48 2011  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* ext/date/date_core.c (wholenum): fix the type of the return value.
+
 Tue Dec 20 05:03:24 2011  Eric Hodel  <drbrain@segment7.net>
 
 	* README.ja:  Update redmine.ruby-lang.org to bugs.ruby-lang.org
diff --git a/ext/date/date_core.c b/ext/date/date_core.c
index 98c05b810d..49e125c3dd 100644
--- a/ext/date/date_core.c
+++ b/ext/date/date_core.c
@@ -3095,7 +3095,7 @@ wholenum_p(VALUE x)
     return 0;
 }
 
-inline static int
+inline static VALUE
 wholenum(VALUE x)
 {
     if (FIXNUM_P(x))