diff --git a/.travis.yml b/.travis.yml
index 7162d1e3..868c01af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,7 +8,7 @@ dist: trusty
 sudo: required
 
 # OS X only supports one image. Use the latest.
-osx_image: xcode9.1
+osx_image: xcode9.4
 
 git:
   depth: 3