diff --git a/.travis.yml b/.travis.yml
index 78d05b000..13c94866f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -67,7 +67,7 @@ matrix:
         apt:
           sources: ['ubuntu-toolchain-r-test']
           packages: ['libstdc++-5-dev']
-      env: CLANG_VERSION='3.9.1' BUILD_TYPE='Release' ENABLE_MASON=ON RUN_CLANG_FORMAT=ON
+      env: CLANG_VERSION='3.9.1' BUILD_TYPE='Release' ENABLE_MASON=ON RUN_CLANG_FORMAT=ON ENABLE_LTO=ON
 
     - os: linux
       compiler: "gcc-6-release"
@@ -95,7 +95,7 @@ matrix:
       osx_image: xcode8.2
       compiler: "mason-osx-release"
       # we use the xcode provides clang and don't install our own
-      env: ENABLE_MASON=ON BUILD_TYPE='Release' CUCUMBER_TIMEOUT=60000 CCOMPILER='clang' CXXCOMPILER='clang++' ENABLE_ASSERTIONS=ON
+      env: ENABLE_MASON=ON BUILD_TYPE='Release' CUCUMBER_TIMEOUT=60000 CCOMPILER='clang' CXXCOMPILER='clang++' ENABLE_ASSERTIONS=ON ENABLE_LTO=ON
 
       # Disabled because of CI slowness
       #- os: linux