diff --git a/.tmux.conf b/.tmux.conf
index e0873d1..adab24a 100644
--- a/.tmux.conf
+++ b/.tmux.conf
@@ -22,7 +22,10 @@ bind-key a send-prefix
 #set -s escape-time 0
 
 # Highlight active window
-set-window-option -g window-status-current-bg red
+# before tmux 2.9
+#set-window-option -g window-status-current-bg red
+# since tmux 2.9:
+set-window-option -g window-status-current-style bg=red
 
 #split panes using | and -
 bind | split-window -h