diff --git a/behaviour.el b/behaviour.el
index 197205b..1f36012 100644
--- a/behaviour.el
+++ b/behaviour.el
@@ -6,3 +6,6 @@
   (if (eq (window-main-window) (selected-window))
       (if (equal (buffer-name) "*dashboard*") nil (kill-buffer))
       (evil-window-delete)))
+
+(with-eval-after-load 'treemacs
+  (define-key treemacs-mode-map [mouse-1] #'treemacs-single-click-expand-action))