diff --git a/ChangeLog b/ChangeLog
index 6849185ba5..070513235a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jun 30 11:05:59 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* dln.c (dln_find_1): fixed index overrun.
+
 Tue Jun 30 08:42:34 2009  Eric Hodel  <drbrain@segment7.net>
 
 	* tool/instruby.rb: summary is required in a .gemspec.
diff --git a/dln.c b/dln.c
index 484dab5d1d..b939dc3460 100644
--- a/dln.c
+++ b/dln.c
@@ -1563,8 +1563,8 @@ dln_find_1(const char *fname, const char *path, char *fbuf, size_t size,
 	}
     }
     if (ext) {
-	for (j = 0; STRCASECMP(ext, extension[j]); j++) {
-	    if (j == sizeof(extension) / sizeof(extension[0])) {
+	for (j = 0; STRCASECMP(ext, extension[j]); ) {
+	    if (++j == sizeof(extension) / sizeof(extension[0])) {
 		ext = 0;
 		break;
 	    }