diff --git a/sandbox/Dockerfile b/sandbox/Dockerfile
index bec94c5..4cabc3d 100644
--- a/sandbox/Dockerfile
+++ b/sandbox/Dockerfile
@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-FROM golang:1.5
+FROM golang:1.6
 
 # enable faketime
 RUN apt-get update && apt-get install -yq --no-install-recommends patch