diff --git a/README.md b/README.md
index 1297b659..88250c71 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,12 @@ online example: http://react-component.github.io/input-number/examples/
           <td>rc-input-number</td>
           <td>Specifies the class prefix</td>
         </tr>
+        <tr>
+          <td>inputClassName</td>
+          <td>string</td>
+          <td></td>
+          <td>Specifies the class of the html input field</td>
+        </tr>
         <tr>
           <td>min</td>
           <td>Number</td>
diff --git a/src/InputNumber.tsx b/src/InputNumber.tsx
index 25e9fad1..0193156e 100644
--- a/src/InputNumber.tsx
+++ b/src/InputNumber.tsx
@@ -681,6 +681,7 @@ class InputNumber extends React.Component<Partial<InputNumberProps>, InputNumber
       upHandler,
       downHandler,
       className,
+      inputClassName,
       max,
       min,
       style,
@@ -814,7 +815,7 @@ class InputNumber extends React.Component<Partial<InputNumberProps>, InputNumber
             onPaste={onPaste}
             onClick={onClick}
             onMouseUp={this.onMouseUp}
-            className={`${prefixCls}-input`}
+            className={`${prefixCls}-input ${inputClassName}`}
             tabIndex={tabIndex}
             autoComplete={autoComplete}
             onFocus={this.onFocus}
diff --git a/src/interface.ts b/src/interface.ts
index bee59356..de645b47 100644
--- a/src/interface.ts
+++ b/src/interface.ts
@@ -6,6 +6,7 @@ export interface InputNumberProps {
   prefixCls?: string;
   style: React.CSSProperties;
   className?: string;
+  inputClassName?: string;
   onKeyUp: (e, ...arg) => void;
   onKeyDown: (e, ...arg) => void;
   onMouseUp: (...arg) => void;