diff --git a/CI/before_script.osx.sh b/CI/before_script.osx.sh
index 3a789bef77..2175de0cd4 100755
--- a/CI/before_script.osx.sh
+++ b/CI/before_script.osx.sh
@@ -22,7 +22,6 @@ declare -a CMAKE_CONF_OPTS=(
 -D CMAKE_CXX_COMPILER_LAUNCHER="$CCACHE_EXECUTABLE"
 -D CMAKE_CXX_FLAGS="-stdlib=libc++"
 -D CMAKE_OSX_DEPLOYMENT_TARGET="13.6"
--D OPENMW_USE_SYSTEM_OSG=TRUE
 -D OPENMW_USE_SYSTEM_RECASTNAVIGATION=TRUE
 -D Boost_INCLUDE_DIR="$DEPENDENCIES_ROOT/include"
 -D OSGPlugins_LIB_DIR="$DEPENDENCIES_ROOT/lib/osgPlugins-3.6.5"