diff --git a/demo/vis.py b/demo/vis.py
index 2968c2e70..8f977a178 100755
--- a/demo/vis.py
+++ b/demo/vis.py
@@ -65,7 +65,7 @@ def show3Dpose(vals, ax):
 
     ax.set_xlim3d([-RADIUS, RADIUS])
     ax.set_ylim3d([-RADIUS, RADIUS])
-    ax.set_aspect('equal')
+    ax.set_aspect('equal') # works fine in matplotlib==2.2.2
 
     white = (1.0, 1.0, 1.0, 0.0)
     ax.xaxis.set_pane_color(white)