diff --git a/ChangeLog b/ChangeLog
index c165886b67..721ad4b9d8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul  3 21:20:45 2008  Yusuke Endoh  <mame@tsg.ne.jp>
+
+	* thread.c (thread_initialize): NUM2INT returns long.
+
 Thu Jul  3 21:06:16 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* eval.c (Init_eval): typo fixed in r17833.
diff --git a/thread.c b/thread.c
index b021e2e337..432a91d331 100644
--- a/thread.c
+++ b/thread.c
@@ -490,7 +490,7 @@ thread_initialize(VALUE thread, VALUE args)
 	    rb_raise(rb_eThreadError, "already initialized thread - %s",
 		     file);
 	}
-        rb_raise(rb_eThreadError, "already initialized thread - %s:%d",
+        rb_raise(rb_eThreadError, "already initialized thread - %s:%ld",
                  file, NUM2INT(line));
     }
     return thread_create_core(thread, args, 0);