diff --git a/http.c b/http.c
index 0a8abf3be3..44f35256e4 100644
--- a/http.c
+++ b/http.c
@@ -236,6 +236,7 @@ static int has_cert_password(void)
 		return 0;
 	if (!cert_auth.password) {
 		cert_auth.protocol = xstrdup("cert");
+		cert_auth.username = xstrdup("");
 		cert_auth.path = xstrdup(ssl_cert);
 		credential_fill(&cert_auth);
 	}