diff --git a/.travis.yml b/.travis.yml
index e9866985..7ebadee7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -25,8 +25,8 @@ matrix:
         - BUILD_ARCH=x86_64
         - BUILD_PLATFORM=darwin
       before_install:
-        - brew upgrade
-        - brew install cmake
+        - brew update
+        - brew outdated cmake || brew upgrade cmake
 
 script:
   - if [ "$CC" = "gcc" ]; then export CC="gcc-6" CXX="g++-6"; fi