diff --git a/.travis.yml b/.travis.yml
index 4fa9e541..bd08e992 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -13,5 +13,6 @@ matrix:
     - os: osx
       compiler: clang
 script:
+  - export CFLAGS=-Werror
   - make clean
   - make