diff --git a/ChangeLog b/ChangeLog
index d1dc7117dc..5b4ec27e0a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Dec 20 16:42:55 2007  Koichi Sasada  <ko1@atdot.net>
+
+	* iseq.c (find_line_no): return 0 if not found.
+
 Thu Dec 20 16:04:17 2007  Koichi Sasada  <ko1@atdot.net>
 
 	* insnhelper.ci, vm.c, vm_core.h: change interface of
diff --git a/iseq.c b/iseq.c
index 6ad0e8d25a..f316edab30 100644
--- a/iseq.c
+++ b/iseq.c
@@ -559,6 +559,9 @@ find_line_no(rb_iseq_t *iseq, unsigned long pos)
     if (entry) {
 	return entry->line_no;
     }
+    else {
+	return 0;
+    }
 }
 
 static unsigned short