diff --git a/docs/src/pages/component-api/MobileStepper/MobileStepper.md b/docs/src/pages/component-api/MobileStepper/MobileStepper.md
index cfa97aa210cd74..b4d5bc41432970 100644
--- a/docs/src/pages/component-api/MobileStepper/MobileStepper.md
+++ b/docs/src/pages/component-api/MobileStepper/MobileStepper.md
@@ -25,6 +25,7 @@ This property accepts the following keys:
 - `dots`
 - `dot`
 - `dotActive`
+- `progressClassName`
 
 Have a look at [overriding with class names](/customization/overrides#overriding-with-class-names)
 section for more detail.
diff --git a/src/MobileStepper/MobileStepper.js b/src/MobileStepper/MobileStepper.js
index 0376d8d23b74e5..54e77b90c75702 100644
--- a/src/MobileStepper/MobileStepper.js
+++ b/src/MobileStepper/MobileStepper.js
@@ -42,7 +42,7 @@ export const styleSheet = createStyleSheet('MuiMobileStepper', theme => ({
   },
   progressClassName: {
     width: '50%',
-  }
+  },
 }));
 
 function MobileStepper(props) {
@@ -145,6 +145,10 @@ MobileStepper.propTypes = {
    * Passed into the onTouchTap prop of the Next button.
    */
   onNext: PropTypes.func.isRequired,
+  /**
+   * @ignore
+   */
+  progressClassName: PropTypes.string,
   /**
    * The total steps.
    */