diff --git a/backend/src/services/integration-auth/integration-sync-secret.ts b/backend/src/services/integration-auth/integration-sync-secret.ts
index 83bf2616c..249307f8d 100644
--- a/backend/src/services/integration-auth/integration-sync-secret.ts
+++ b/backend/src/services/integration-auth/integration-sync-secret.ts
@@ -1636,7 +1636,7 @@ const syncSecretsVercel = async ({
                 }
               : {
                   customEnvironmentIds: res[key].customEnvironmentIds?.includes(integration.targetEnvironment as string)
-                    ? [...res[key].customEnvironmentIds]
+                    ? [...(res[key].customEnvironmentIds || [])]
                     : [...(res[key]?.customEnvironmentIds || []), integration.targetEnvironment as string]
                 }),