diff --git a/.travis.yml b/.travis.yml
index 8189e933d..a736c4f1b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,7 +22,7 @@ before_install:
 - git submodule update --init --recursive
 - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then 
   brew update;
-  brew install freetype libevent sqlite dylibbundler;
+  brew install freetype libevent sqlite dylibbundler p7zip;
   sudo rm -rf /usr/local/include/unistring;
   sudo rm -rf /usr/local/include/lzma;
   sudo rm -f /usr/local/include/CGAL/stddef.h; fi