diff --git a/lib/url.c b/lib/url.c
index 51515c924d..086e214e47 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -2310,7 +2310,7 @@ static CURLcode parse_proxy(struct Curl_easy *data,
                             struct connectdata *conn, char *proxy,
                             curl_proxytype proxytype)
 {
-  char *portptr;
+  char *portptr = NULL;
   long port = -1;
   char *proxyuser = NULL;
   char *proxypasswd = NULL;