diff --git a/modules/tmux/init.zsh b/modules/tmux/init.zsh
index aadf6bf..720fb04 100644
--- a/modules/tmux/init.zsh
+++ b/modules/tmux/init.zsh
@@ -37,8 +37,8 @@ if [[ -z "$TMUX" && -z "$EMACS" && -z "$VIM" ]] && ( \
       set-option -t "$tmux_session" destroy-unattached off &> /dev/null
   fi
 
-  # Attach to the 'prezto' session or to the last session used.
-  exec tmux $_tmux_iterm_integration attach-session
+  # Attach to the 'prezto' session or to the last session used. (detach first)
+  exec tmux $_tmux_iterm_integration attach-session -d
 fi
 
 #