diff --git a/script/build-osx b/script/build-osx
index ee011d1b2..7cba87029 100755
--- a/script/build-osx
+++ b/script/build-osx
@@ -1,5 +1,6 @@
 #!/bin/bash
 set -ex
+rm -r venv
 virtualenv venv
 venv/bin/pip install pyinstaller==2.1
 venv/bin/pip install .