diff --git a/bin/homedir-gems b/bin/homedir-gems
--- a/bin/homedir-gems
+++ b/bin/homedir-gems
@@ -1,4 +1,6 @@
 #!/bin/sh
 set -eu
 
+bundle --version || gem install bundler
+
 exec bundle install --system --jobs=2 --gemfile=~/.Gemfile