diff --git a/guestbook/guestbook-ui-deployment.yaml b/guestbook/guestbook-ui-deployment.yaml
index 34f9e21..c57bbeb 100644
--- a/guestbook/guestbook-ui-deployment.yaml
+++ b/guestbook/guestbook-ui-deployment.yaml
@@ -23,6 +23,6 @@ spec:
         readinessProbe:
           exec:
             command:
-            - true
+            - "true"
           initialDelaySeconds: 30
-          periodSeconds: 30
+          periodSeconds: 30
\ No newline at end of file