diff --git a/apps/slopeclockpp/app.js b/apps/slopeclockpp/app.js
index 359993bc3..df732c1db 100644
--- a/apps/slopeclockpp/app.js
+++ b/apps/slopeclockpp/app.js
@@ -86,6 +86,7 @@ let draw = function() {
 
 let isAnimIn = true;
 let animInterval;
+let minuteX;
 // Draw *just* the minute image
 let drawMinute = function() {
   var yo = slopeBorder + offsy + y - 2*slope*minuteX/R.w;