diff --git a/scripts/setup-osx.sh b/scripts/setup-osx.sh
index f9c303412..d363179f3 100644
--- a/scripts/setup-osx.sh
+++ b/scripts/setup-osx.sh
@@ -5,4 +5,4 @@ sudo python3 -m ensurepip --upgrade
 # A manual check that the correct version of Python is running.
 python3 --version
 python3 -m pip install -r requirements.txt
-python3 -m pip install PyInstaller
+python3 -m pip install PyInstaller==3.3