I have following custom zsh keybindings for the alt (meta) + left and right arrow key withi os x Iterm2 and +Esc setting for meta

bindkey "^[^[[D" backward-word bindkey "^[^[[C" forward-word 

This allows to jump by word on the shell like in most gui text editors with alt arrow.

However when starting tmux session those bindings just print following on the screen.

DCDCDC 

Any idea how to make zsh within tmux accept the bindings.