diff --git a/web/components/button.react.js b/web/components/button.react.js
--- a/web/components/button.react.js
+++ b/web/components/button.react.js
@@ -28,6 +28,7 @@
 
 export type ButtonProps = {
   +onClick: ?(event: SyntheticEvent<HTMLButtonElement>) => mixed,
+  +onMouseOver?: ?(event: SyntheticEvent<HTMLButtonElement>) => mixed,
   +children: React.Node,
   +variant?: ButtonVariant,
   +buttonColor?: ButtonColor,
@@ -39,6 +40,7 @@
 function Button(props: ButtonProps): React.Node {
   const {
     onClick,
+    onMouseOver,
     children,
     variant = 'plain',
     buttonColor,
@@ -74,6 +76,7 @@
       type={type}
       className={`${btnCls} ${className}`}
       onClick={onClick}
+      onMouseOver={onMouseOver}
       disabled={disabled}
       style={style}
     >