diff --git a/internal/api/external.go b/internal/api/external.go
index b4df15a46..e6c424902 100644
--- a/internal/api/external.go
+++ b/internal/api/external.go
@@ -679,7 +679,7 @@ func (a *API) loadCustomProvider(ctx context.Context, db *storage.Connection, id
 	var pConfig conf.OAuthProviderConfiguration
 
 	// Build the redirect URL
-	redirectURL := config.API.ExternalURL + "/callback"
+	redirectURL := config.API.ExternalURL + "/auth/v1/callback"
 
 	// Parse scopes (space-separated per RFC 6749)
 	var scopeList []string