diff --git a/.travis.yml b/.travis.yml
index 3915f25..26399a3 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,7 @@
+# https://blog.travis-ci.com/2017-06-21-trusty-updates-2017-Q2-launch
+# Reverts Trusty build environment version, because 2017Q2 is broken for OrderedDict.
+group: deprecated-2017Q2
+
 language: python
 
 python: "3.6"