diff --git a/.travis.yml b/.travis.yml
index 2d0d4ea7..4a8324b8 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,8 @@ compiler:
 
 addons:
   apt:
+    sources:
+     - ubuntu-toolchain-r-test
     packages:
      - g++-5
      - autotools-dev