diff --git a/sandbox/Dockerfile b/sandbox/Dockerfile
index 38bac72..b65c849 100644
--- a/sandbox/Dockerfile
+++ b/sandbox/Dockerfile
@@ -7,7 +7,7 @@
 ENV GOPATH /go
 ENV PATH /usr/local/go/bin:$GOPATH/bin:$PATH
 ENV GOROOT_BOOTSTRAP /usr/local/gobootstrap
-ENV GO_VERSION 1.8
+ENV GO_VERSION 1.9
 
 # Fake time
 COPY enable-fake-time.patch /usr/local/sandbox/