diff --git a/ext/rugged/rugged_remote.c b/ext/rugged/rugged_remote.c
index e9c93d45e..2e79d6f4e 100644
--- a/ext/rugged/rugged_remote.c
+++ b/ext/rugged/rugged_remote.c
@@ -152,6 +152,9 @@ static int credentials_cb(
 
 	rb_protect(extract_cred, (VALUE)&args, &payload->exception);
 
+	if (!*cred)
+		return GIT_PASSTHROUGH;
+
 	return payload->exception ? GIT_ERROR : GIT_OK;
 }