diff --git a/modules/Slider.js b/modules/Slider.js
index d80a9f910..a617f91f1 100644
--- a/modules/Slider.js
+++ b/modules/Slider.js
@@ -13,7 +13,7 @@ try { // For making it possiblie to run the test app in the following catch stat
 
     // Default configuration for the indicator, modified by parameter `conf`:
     o.c = Object.assign({ // constants go here.
-      currLevel:undefined,
+      currLevel:null,
       horizontal:false,
       xStart:R.x2-R.w/4-4,
       width:R.w/4,
@@ -65,7 +65,7 @@ try { // For making it possiblie to run the test app in the following catch stat
     o.c.r = {x:o.c.xStart, y:o.c.yStart, x2:o.c.xStart+o.c.width, y2:o.c.yStart+o.c.height, w:o.c.width, h:o.c.height};
 
     // Initialize the level
-    o.v.level = (o.c.currLevel||o.c.currLevel===0)?o.c.currLevel:o.c.steps/2;
+    o.v.level = o.c.currLevel!==null?o.c.currLevel:o.c.steps/2;
 
     // Only add interactivity if wanted.
     if (o.c.dragableSlider) {