diff --git a/.travis/install-macos.sh b/.travis/install-macos.sh
index 6fb5a4f..1214dd4 100755
--- a/.travis/install-macos.sh
+++ b/.travis/install-macos.sh
@@ -1,4 +1,3 @@
 #!/bin/sh -xe
 
 brew update
-brew upgrade cmake libpng