updated properties
diff --git a/gce-properties.yml b/gce-properties.yml
index 0129328..20fe939 100644
--- a/gce-properties.yml
+++ b/gce-properties.yml
@@ -1,4 +1,5 @@
 ---
+credentials_file: ~/.ansible/access/default-service-account.json
 machine_type: 'n1-standard-1'
 image: 'centos-7-v20170918'
 zone: 'us-east1-b'