diff --git a/tools/clog-builder-project-tree.lisp b/tools/clog-builder-project-tree.lisp
index 926e591..b762daa 100644
--- a/tools/clog-builder-project-tree.lisp
+++ b/tools/clog-builder-project-tree.lisp
@@ -71,6 +71,11 @@
                                      (setf (project-tree-win app) nil)))
           (setf (positioning projects) :absolute)
           (set-geometry projects :height 27 :width "100%" :top 0 :left 0 :right 0)
+          (set-on-click (create-span (window-icon-area win) :content "← ")
+                        (lambda (obj)
+                          (declare (ignore obj))
+                          (set-geometry win :top (menu-bar-height win) :left 0 :height "" :bottom 5 :right "")
+                          :auto-place :top))
           (set-on-click filter-btn (lambda (obj)
                                      (declare (ignore obj))
                                      (if (equalp (text-value filter-btn)