diff --git a/bin/safe-reattach-to-user-namespace b/bin/safe-reattach-to-user-namespace
new file mode 100755
index 0000000..53abbfc
--- /dev/null
+++ b/bin/safe-reattach-to-user-namespace
@@ -0,0 +1,8 @@
+#! /usr/bin/env bash
+
+# If reattach-to-user-namespace is not available, just run the command.
+if [ -n "$(command -v reattach-to-user-namespace)" ]; then
+  reattach-to-user-namespace $@
+else
+  exec "$@"
+fi
diff --git a/tmux.conf b/tmux.conf
index b8729d9..98a786c 100644
--- a/tmux.conf
+++ b/tmux.conf
@@ -12,6 +12,9 @@ set -g mouse-resize-pane on
 set -g mouse-select-window on
 set -g history-limit 10240
 
+# Mac OS X fix for pbcopy, pbpaste, and launchctl
+set-option -g default-command "safe-reattach-to-user-namespace -l $SHELL"
+
 # Load Theme
 source-file "${HOME}/.tmux/themes/powerline-block-green.tmuxtheme"