diff --git a/tmux/macos.conf b/tmux/macos.conf
new file mode 100644
index 0000000..23db35a
--- /dev/null
+++ b/tmux/macos.conf
@@ -0,0 +1,6 @@
+# osx clipboard
+set-option -g default-command "which reattach-to-user-namespace > /dev/null && reattach-to-user-namespace -l $SHELL || $SHELL"
+
+# Undercurl
+set -as terminal-overrides ',*:Smulx=\E[4::%p1%dm'  # undercurl support
+set -as terminal-overrides ',*:Setulc=\E[58::2::%p1%{65536}%/%d::%p1%{256}%/%{255}%&%d::%p1%{255}%&%d%;m'  # underscore colours - needs tmux-3.0