diff --git a/src/matrix/net/OidcApi.ts b/src/matrix/net/OidcApi.ts
index 832c94e7..1d0db462 100644
--- a/src/matrix/net/OidcApi.ts
+++ b/src/matrix/net/OidcApi.ts
@@ -90,7 +90,7 @@ export class OidcApi {
     }
 
     get metadataUrl() {
-        return new URL(WELL_KNOWN, this._issuer).toString();
+        return new URL(WELL_KNOWN, `${this._issuer}${this._issuer.endsWith('/') ? '' : '/'}`).toString();
     }
 
     get issuer() {