diff --git a/lib/documentListeners.js b/lib/documentListeners.js
index c0972f4b6..dcc44972e 100644
--- a/lib/documentListeners.js
+++ b/lib/documentListeners.js
@@ -21,7 +21,10 @@ function inputIsNumberValue(input) {
   return (type === 'number' || (type === 'range' && !input.multiple));
 }
 var inputValue = function(input) {
-  return inputIsNumberValue(input) ? input.valueAsNumber : input.value;
+  if (!inputIsNumberValue(input))
+    return input.value;
+  else
+    return (isFinite(input.valueAsNumber)) ? input.valueAsNumber : '';
 };
 
 function addDocumentListeners(doc) {