diff --git a/docs/src/modules/components/AppTableOfContents.js b/docs/src/modules/components/AppTableOfContents.js
index 1799a536444806..beb4d7a1e8fedc 100644
--- a/docs/src/modules/components/AppTableOfContents.js
+++ b/docs/src/modules/components/AppTableOfContents.js
@@ -23,6 +23,7 @@ const Nav = styled('nav')(({ theme }) => ({
   paddingBottom: theme.spacing(7),
   paddingRight: theme.spacing(4), // We can't use `padding` as stylis-plugin-rtl doesn't swap it
   display: 'none',
+  scrollbarWidth: 'thin',
   [theme.breakpoints.up('md')]: {
     display: 'block',
   },