diff --git a/urlmatch.h b/urlmatch.h
index 37ee5da85e..e482148248 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -1,4 +1,6 @@
 #ifndef URL_MATCH_H
+#define URL_MATCH_H
+
 #include "string-list.h"
 
 struct url_info {