diff --git a/.travis.yml b/.travis.yml
index 7d4f5446c..366a23aa2 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -12,6 +12,7 @@ sudo: required
 dist: trusty
 addons:
   apt:
+    update: true
     sources:
       - ubuntu-toolchain-r-test
       - llvm-toolchain-trusty-4.0