diff --git a/app/appengine/app.yaml b/app/appengine/app.yaml
index 915e1fe..9657aff 100644
--- a/app/appengine/app.yaml
+++ b/app/appengine/app.yaml
@@ -1,5 +1,5 @@
 runtime: go
-api_version: go1.8
+api_version: go1.9
 
 handlers:
 - url: /static