diff --git a/CI/before_install.osx.sh b/CI/before_install.osx.sh
index 28acae13c..c6cf797e0 100755
--- a/CI/before_install.osx.sh
+++ b/CI/before_install.osx.sh
@@ -4,7 +4,8 @@
 command -v ccache >/dev/null 2>&1 || brew install ccache
 command -v cmake >/dev/null 2>&1 || brew install cmake
 command -v qmake >/dev/null 2>&1 || brew install qt
-command -v lz4 >/dev/null 2>&1 || brew install lz4
+brew reinstall lz4
 
 curl -fSL -R -J https://downloads.openmw.org/osx/dependencies/openmw-deps-ef2462c.zip -o ~/openmw-deps.zip
+rm -fr /tmp/openmw-deps
 unzip -o ~/openmw-deps.zip -d /private/tmp/openmw-deps > /dev/null