diff --git a/.travis.yml b/.travis.yml
index ae38617b996..869507a9fd6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,6 +30,7 @@ rvm:
 matrix:
   allow_failures:
     - rvm: ruby-head
+    - env: "GEM=ac"
   fast_finish: true
 notifications:
   email: false