diff --git a/macbuild.tool b/macbuild.tool
index 097e5e87a5f..8a2dc4e588b 100755
--- a/macbuild.tool
+++ b/macbuild.tool
@@ -1,5 +1,8 @@
 #!/bin/bash
 
+unset WORKSPACE
+unset PACKAGES_PATH
+
 BUILDDIR=$(dirname "$0")
 pushd "$BUILDDIR" >/dev/null
 BUILDDIR=$(pwd)