diff --git a/bin/fzf-tmux b/bin/fzf-tmux
index 8b04c5ba..a164a626 100755
--- a/bin/fzf-tmux
+++ b/bin/fzf-tmux
@@ -83,7 +83,7 @@ while [ $# -gt 0 ]; do
   shift
 done
 
-if ! [ -n "$TMUX_PANE" -a $lines -gt 15 ]; then
+if ! [ -n "$TMUX" -a "$lines" -gt 15 ]; then
   fzf "${args[@]}"
   exit $?
 fi