No clue if you've done these steps, and I'm not on Mac OS at the moment (also I use Terminal.app), but: In my main .tmux.conf I put: if-shell 'test "$(uname

No clue if you've done these steps, and I'm not on Mac OS at the moment (also I use Terminal.app), but: In my main .tmux.conf I put: if-shell 'test "$(uname -s)" = Darwin' 'source-file ~/.tmux-osx.conf' And then in .tmux-osx.conf I add: # https://robots.thoughtbot.com/tmux-copy-paste-on-os-x-a-better-future # To copy/paste on OSX just brew install the following # brew install reattach-to-user-namespace # Setup 'v' to begin selection as in Vim bind-key -t vi-copy v begin-selection bind-key -t vi-copy y copy-pipe "reattach-to-user-namespace pbcopy" # Update default binding of `Enter` to also use copy-pipe unbind -t vi-copy Enter bind-key -t vi-copy Enter copy-pipe "reattach-to-user-namespace pbcopy" I only pointed out the separation of configs because it's kinda nice for my setup.