diff --git a/deployment/deploy-yml.tmpl b/deployment/deploy-yml.tmpl
index 5c93fa5..6c978fb 100644
--- a/deployment/deploy-yml.tmpl
+++ b/deployment/deploy-yml.tmpl
@@ -22,7 +22,7 @@ spec:
               protocol: TCP
           env:
             - name: JUPYTER_PORT
-              value: 8888
+              value: "8888"
 ---
 apiVersion: v1
 kind: Service