diff --git a/docs/src/modules/components/AppContent.js b/docs/src/modules/components/AppContent.js
index 5262b4eb2eaade..e105a2db387c70 100644
--- a/docs/src/modules/components/AppContent.js
+++ b/docs/src/modules/components/AppContent.js
@@ -36,7 +36,7 @@ function AppContent(props) {
     <Container
       component="main"
       id="main-content"
-      tabIndex="-1"
+      tabIndex={-1}
       className={clsx(classes.root, className, {
         [classes.disableToc]: disableToc,
       })}
diff --git a/docs/src/pages/demos/tabs/IconTabs.js b/docs/src/pages/demos/tabs/IconTabs.js
index 0257e80c22fa92..e64f3ea8dc0490 100644
--- a/docs/src/pages/demos/tabs/IconTabs.js
+++ b/docs/src/pages/demos/tabs/IconTabs.js
@@ -31,9 +31,9 @@ function IconTabs() {
         indicatorColor="primary"
         textColor="primary"
       >
-        <Tab icon={<PhoneIcon />} />
-        <Tab icon={<FavoriteIcon />} />
-        <Tab icon={<PersonPinIcon />} />
+        <Tab icon={<PhoneIcon />} aria-label="Phone" />
+        <Tab icon={<FavoriteIcon />} aria-label="Favorite" />
+        <Tab icon={<PersonPinIcon />} aria-label="Person" />
       </Tabs>
     </Paper>
   );
diff --git a/docs/src/pages/demos/tabs/IconTabs.tsx b/docs/src/pages/demos/tabs/IconTabs.tsx
index 65f1e4fe95f04f..fc2efdbef4e6d8 100644
--- a/docs/src/pages/demos/tabs/IconTabs.tsx
+++ b/docs/src/pages/demos/tabs/IconTabs.tsx
@@ -31,9 +31,9 @@ function IconTabs() {
         indicatorColor="primary"
         textColor="primary"
       >
-        <Tab icon={<PhoneIcon />} />
-        <Tab icon={<FavoriteIcon />} />
-        <Tab icon={<PersonPinIcon />} />
+        <Tab icon={<PhoneIcon />} aria-label="Phone" />
+        <Tab icon={<FavoriteIcon />} aria-label="Favorite" />
+        <Tab icon={<PersonPinIcon />} aria-label="Person" />
       </Tabs>
     </Paper>
   );
diff --git a/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.js b/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.js
index 16eb7b1ddf46a9..e58b5f98282dfb 100644
--- a/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.js
+++ b/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.js
@@ -45,13 +45,13 @@ function ScrollableTabsButtonPrevent() {
     <div className={classes.root}>
       <AppBar position="static">
         <Tabs value={value} onChange={handleChange} variant="scrollable" scrollButtons="off">
-          <Tab icon={<PhoneIcon />} />
-          <Tab icon={<FavoriteIcon />} />
-          <Tab icon={<PersonPinIcon />} />
-          <Tab icon={<HelpIcon />} />
-          <Tab icon={<ShoppingBasket />} />
-          <Tab icon={<ThumbDown />} />
-          <Tab icon={<ThumbUp />} />
+          <Tab icon={<PhoneIcon />} aria-label="Phone" />
+          <Tab icon={<FavoriteIcon />} aria-label="Favorite" />
+          <Tab icon={<PersonPinIcon />} aria-label="Person" />
+          <Tab icon={<HelpIcon />} aria-label="Help" />
+          <Tab icon={<ShoppingBasket />} aria-label="Shopping" />
+          <Tab icon={<ThumbDown />} aria-label="Up" />
+          <Tab icon={<ThumbUp />} aria-label="Down" />
         </Tabs>
       </AppBar>
       {value === 0 && <TabContainer>Item One</TabContainer>}
diff --git a/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.tsx b/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.tsx
index 82aafa5155fa4a..be0d8652bb1a37 100644
--- a/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.tsx
+++ b/docs/src/pages/demos/tabs/ScrollableTabsButtonPrevent.tsx
@@ -49,13 +49,13 @@ function ScrollableTabsButtonPrevent() {
     <div className={classes.root}>
       <AppBar position="static">
         <Tabs value={value} onChange={handleChange} variant="scrollable" scrollButtons="off">
-          <Tab icon={<PhoneIcon />} />
-          <Tab icon={<FavoriteIcon />} />
-          <Tab icon={<PersonPinIcon />} />
-          <Tab icon={<HelpIcon />} />
-          <Tab icon={<ShoppingBasket />} />
-          <Tab icon={<ThumbDown />} />
-          <Tab icon={<ThumbUp />} />
+          <Tab icon={<PhoneIcon />} aria-label="Phone" />
+          <Tab icon={<FavoriteIcon />} aria-label="Favorite" />
+          <Tab icon={<PersonPinIcon />} aria-label="Person" />
+          <Tab icon={<HelpIcon />} aria-label="Help" />
+          <Tab icon={<ShoppingBasket />} aria-label="Shopping" />
+          <Tab icon={<ThumbDown />} aria-label="Up" />
+          <Tab icon={<ThumbUp />} aria-label="Down" />
         </Tabs>
       </AppBar>
       {value === 0 && <TabContainer>Item One</TabContainer>}
diff --git a/packages/material-ui/src/Backdrop/Backdrop.js b/packages/material-ui/src/Backdrop/Backdrop.js
index 73b96b33f9f2cc..9619d3d694f2a8 100644
--- a/packages/material-ui/src/Backdrop/Backdrop.js
+++ b/packages/material-ui/src/Backdrop/Backdrop.js
@@ -39,7 +39,7 @@ const Backdrop = React.forwardRef(function Backdrop(props, ref) {
           },
           className,
         )}
-        aria-hidden="true"
+        aria-hidden
         ref={ref}
       />
     </Fade>
diff --git a/packages/material-ui/src/Breadcrumbs/BreadcrumbSeparator.js b/packages/material-ui/src/Breadcrumbs/BreadcrumbSeparator.js
index a87d4d6924498d..94f30067de0f26 100644
--- a/packages/material-ui/src/Breadcrumbs/BreadcrumbSeparator.js
+++ b/packages/material-ui/src/Breadcrumbs/BreadcrumbSeparator.js
@@ -18,7 +18,7 @@ const styles = {
 function BreadcrumbSeparator(props) {
   const { classes, className, ...other } = props;
 
-  return <li aria-hidden="true" className={clsx(classes.root, className)} {...other} />;
+  return <li aria-hidden className={clsx(classes.root, className)} {...other} />;
 }
 
 BreadcrumbSeparator.propTypes = {
diff --git a/packages/material-ui/src/ButtonBase/ButtonBase.js b/packages/material-ui/src/ButtonBase/ButtonBase.js
index 4dbaaa4125e79f..4977ab46a75d77 100644
--- a/packages/material-ui/src/ButtonBase/ButtonBase.js
+++ b/packages/material-ui/src/ButtonBase/ButtonBase.js
@@ -309,7 +309,7 @@ class ButtonBase extends React.Component {
           setRef(buttonRef, ref);
           setRef(innerRef, ref);
         }}
-        tabIndex={disabled ? '-1' : tabIndex}
+        tabIndex={disabled ? -1 : tabIndex}
         {...buttonProps}
         {...other}
       >
@@ -468,7 +468,7 @@ ButtonBase.defaultProps = {
   disableRipple: false,
   disableTouchRipple: false,
   focusRipple: false,
-  tabIndex: '0',
+  tabIndex: 0,
   type: 'button',
 };
 
diff --git a/packages/material-ui/src/ButtonBase/ButtonBase.test.js b/packages/material-ui/src/ButtonBase/ButtonBase.test.js
index cbda9afd77c743..df764f893f45e5 100644
--- a/packages/material-ui/src/ButtonBase/ButtonBase.test.js
+++ b/packages/material-ui/src/ButtonBase/ButtonBase.test.js
@@ -50,7 +50,7 @@ describe('<ButtonBase />', () => {
     it('should change the button component and add accessibility requirements', () => {
       const wrapper = mount(<ButtonBase component="span" role="checkbox" aria-checked={false} />);
       const checkbox = wrapper.find('span[role="checkbox"]');
-      assert.strictEqual(checkbox.props().tabIndex, '0');
+      assert.strictEqual(checkbox.props().tabIndex, 0);
     });
 
     it('should not apply role="button" if type="button"', () => {
@@ -381,7 +381,7 @@ describe('<ButtonBase />', () => {
   describe('prop: disabled', () => {
     it('should not receive the focus', () => {
       const wrapper = mount(<ButtonBase disabled>Hello</ButtonBase>);
-      assert.strictEqual(wrapper.find('button').props().tabIndex, '-1');
+      assert.strictEqual(wrapper.find('button').props().tabIndex, -1);
     });
 
     it('should also apply it when using component', () => {
diff --git a/packages/material-ui/src/ExpansionPanelSummary/ExpansionPanelSummary.js b/packages/material-ui/src/ExpansionPanelSummary/ExpansionPanelSummary.js
index 8321335d8407a3..b026cf9a6bcf30 100644
--- a/packages/material-ui/src/ExpansionPanelSummary/ExpansionPanelSummary.js
+++ b/packages/material-ui/src/ExpansionPanelSummary/ExpansionPanelSummary.js
@@ -136,7 +136,7 @@ const ExpansionPanelSummary = React.forwardRef(function ExpansionPanelSummary(pr
           edge="end"
           component="div"
           tabIndex={-1}
-          aria-hidden="true"
+          aria-hidden
           {...IconButtonProps}
         >
           {expandIcon}
diff --git a/packages/material-ui/src/Icon/Icon.js b/packages/material-ui/src/Icon/Icon.js
index e876f580bb18a7..375f44b02cba2d 100644
--- a/packages/material-ui/src/Icon/Icon.js
+++ b/packages/material-ui/src/Icon/Icon.js
@@ -63,7 +63,7 @@ const Icon = React.forwardRef(function Icon(props, ref) {
         },
         className,
       )}
-      aria-hidden="true"
+      aria-hidden
       ref={ref}
       {...other}
     />
diff --git a/packages/material-ui/src/InputBase/Textarea.js b/packages/material-ui/src/InputBase/Textarea.js
index 56700d446ee1d2..e1ba65ef600471 100644
--- a/packages/material-ui/src/InputBase/Textarea.js
+++ b/packages/material-ui/src/InputBase/Textarea.js
@@ -127,7 +127,7 @@ const Textarea = React.forwardRef(function Textarea(props, ref) {
         {...other}
       />
       <textarea
-        aria-hidden="true"
+        aria-hidden
         className={props.className}
         readOnly
         ref={shadowRef}
diff --git a/packages/material-ui/src/Modal/SimpleBackdrop.js b/packages/material-ui/src/Modal/SimpleBackdrop.js
index a9bc8678ee8436..97515ecd0c44ae 100644
--- a/packages/material-ui/src/Modal/SimpleBackdrop.js
+++ b/packages/material-ui/src/Modal/SimpleBackdrop.js
@@ -31,7 +31,7 @@ const SimpleBackdrop = React.forwardRef(function SimpleBackdrop(props, ref) {
   return open ? (
     <div
       data-mui-test="Backdrop"
-      aria-hidden="true"
+      aria-hidden
       ref={ref}
       {...other}
       style={{