diff --git a/lib/shared/Configurator.js b/lib/shared/Configurator.js
index 7cb7474023..0c31fdf903 100644
--- a/lib/shared/Configurator.js
+++ b/lib/shared/Configurator.js
@@ -358,7 +358,7 @@ class Configurator {
 
     let input = document.createElement('input');
     input.className = 'vis-configuration vis-config-rangeinput';
-    input.value = range.value;
+    input.value = Number(range.value);
 
     var me = this;
     range.onchange = function () {input.value = this.value; me._update(Number(this.value), path);};