diff --git a/config/packages/league_oauth2_server.yaml b/config/packages/league_oauth2_server.yaml
index 9e6c08d..6f7b9fc 100644
--- a/config/packages/league_oauth2_server.yaml
+++ b/config/packages/league_oauth2_server.yaml
@@ -4,7 +4,7 @@ league_oauth2_server:
         private_key_passphrase: '%env(resolve:OAUTH_PASSPHRASE)%'
         encryption_key: '%env(resolve:OAUTH_ENCRYPTION_KEY)%'
         access_token_ttl: PT15M # 15 minutes
-        refresh_token_ttl: PT7D # 7 days
+        refresh_token_ttl: P7D # 7 days
         auth_code_ttl: PT30M # 30 minutes
         require_code_challenge_for_public_clients: false
     resource_server: