diff --git a/src/config/load.ts b/src/config/load.ts
index 904305647d..1cec3b1485 100644
--- a/src/config/load.ts
+++ b/src/config/load.ts
@@ -59,6 +59,7 @@ function validateUrl(url: string) {
 	const result = tryCreateUrl(url);
 	if (result.pathname.trim('/').length) throw `url="${url}" is not a valid URL, has a pathname.`;
 	if (!url.includes(result.host)) throw `url="${url}" is not a valid URL, has an invalid hostname.`;
+	if (!/^https?:$/.test(result.protocol)) throw `url="${url}" is not a valid URL, has an invalid protocol.`;
 	return result;
 }