diff --git a/lib/http_digest.c b/lib/http_digest.c
index 22ad9b173..76175ef95 100644
--- a/lib/http_digest.c
+++ b/lib/http_digest.c
@@ -36,6 +36,7 @@
 
 #include "md5.h"
 #include "http_digest.h"
+#include "url.h" /* for Curl_safefree() */
 
 #define _MPRINTF_REPLACE /* use our functions only */
 #include <curl/mprintf.h>