diff --git a/url.c b/url.c
index e04bd60..bf318c0 100644
--- a/url.c
+++ b/url.c
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "hex.h"
 #include "url.h"
 
 int is_urlschemechar(int first_flag, int ch)