diff --git a/plugins/auth-oauth2/src/grants/authorizationCode.ts b/plugins/auth-oauth2/src/grants/authorizationCode.ts
index 781cbaab..b1bdb2b3 100644
--- a/plugins/auth-oauth2/src/grants/authorizationCode.ts
+++ b/plugins/auth-oauth2/src/grants/authorizationCode.ts
@@ -56,7 +56,7 @@ export async function getAuthorizationCode(
   try {
     authorizationUrl = new URL(`${authorizationUrlRaw ?? ''}`);
   } catch {
-    throw new Error('Invalid authorization URL: ' + authorizationUrlRaw);
+    throw new Error(`Invalid authorization URL "${authorizationUrlRaw}"`);
   }
   authorizationUrl.searchParams.set('response_type', 'code');
   authorizationUrl.searchParams.set('client_id', clientId);
diff --git a/plugins/auth-oauth2/src/grants/implicit.ts b/plugins/auth-oauth2/src/grants/implicit.ts
index 585f0589..625f255a 100644
--- a/plugins/auth-oauth2/src/grants/implicit.ts
+++ b/plugins/auth-oauth2/src/grants/implicit.ts
@@ -35,7 +35,7 @@ export async function getImplicit(
   try {
     authorizationUrl = new URL(`${authorizationUrlRaw ?? ''}`);
   } catch {
-    throw new Error('Invalid authorization URL: ' + authorizationUrlRaw);
+    throw new Error(`Invalid authorization URL "${authorizationUrlRaw}"`);
   }
   authorizationUrl.searchParams.set('response_type', 'token');
   authorizationUrl.searchParams.set('client_id', clientId);