diff --git a/packages/material-ui/src/Select/Select.test.js b/packages/material-ui/src/Select/Select.test.js
index c2c5340326a252..e6085135285ddf 100644
--- a/packages/material-ui/src/Select/Select.test.js
+++ b/packages/material-ui/src/Select/Select.test.js
@@ -402,10 +402,10 @@ describe('<Select />', () => {
       expect(getByRole('button', { hidden: true })).to.have.attribute('aria-expanded', 'true');
     });
 
-    specify('aria-expanded is not present if the listbox isnt displayed', () => {
+    specify('ARIA 1.2: aria-expanded="false" if the listbox isnt displayed', () => {
       const { getByRole } = render(<Select value="" />);
 
-      expect(getByRole('button')).not.to.have.attribute('aria-expanded');
+      expect(getByRole('button')).to.have.attribute('aria-expanded', 'false');
     });
 
     it('sets aria-disabled="true" when component is disabled', () => {
diff --git a/packages/material-ui/src/Select/SelectInput.js b/packages/material-ui/src/Select/SelectInput.js
index 474107c8cb87ea..037fafc602e7db 100644
--- a/packages/material-ui/src/Select/SelectInput.js
+++ b/packages/material-ui/src/Select/SelectInput.js
@@ -369,7 +369,7 @@ const SelectInput = React.forwardRef(function SelectInput(props, ref) {
         tabIndex={tabIndex}
         role="button"
         aria-disabled={disabled ? 'true' : undefined}
-        aria-expanded={open ? 'true' : undefined}
+        aria-expanded={open ? 'true' : 'false'}
         aria-haspopup="listbox"
         aria-label={ariaLabel}
         aria-labelledby={[labelId, buttonId].filter(Boolean).join(' ') || undefined}