diff --git a/assets/default/dotfiles/tmux.conf b/assets/default/dotfiles/tmux.conf
index f75cd47..dadee09 100644
--- a/assets/default/dotfiles/tmux.conf
+++ b/assets/default/dotfiles/tmux.conf
@@ -33,7 +33,7 @@ bind C-s command-prompt -p "Send pane to:"  "join-pane -t '%%'"
 bind C-b break-pane
 
 # based on https://stackoverflow.com/a/40902312/1046584
-run-shell "tmux setenv -g TMUX_VERSION $(tmux -V | cut -c 6-)"
+run-shell "tmux setenv -g TMUX_VERSION $(tmux -V | sed 's/[^0-9.]//g')"
 
 # In version 2.1 "mouse" replaced the previous 4 mouse options
 if-shell -b '[ "$(echo "$TMUX_VERSION >= 2.1" | bc)" = 1 ]' \