diff --git a/src/components/inputnumber/InputNumber.js b/src/components/inputnumber/InputNumber.js
index 4078cb5126..4549d22c68 100644
--- a/src/components/inputnumber/InputNumber.js
+++ b/src/components/inputnumber/InputNumber.js
@@ -734,6 +734,8 @@ export class InputNumber extends Component {
     }
 
     updateInput(value, insertedValueStr, operation) {
+        insertedValueStr = insertedValueStr || '';
+
         let inputValue = this.inputEl.value;
         let newValue = this.formatValue(value);
         let currentLength = inputValue.length;