diff --git a/packages/mui-material/src/OutlinedInput/OutlinedInput.js b/packages/mui-material/src/OutlinedInput/OutlinedInput.js
index ed8e6bc3945920..9209682528e353 100644
--- a/packages/mui-material/src/OutlinedInput/OutlinedInput.js
+++ b/packages/mui-material/src/OutlinedInput/OutlinedInput.js
@@ -184,7 +184,7 @@ const OutlinedInput = React.forwardRef(function OutlinedInput(inProps, ref) {
             label != null && label !== '' && fcs.required ? (
               <React.Fragment>
                 {label}
-                &nbsp;{'*'}
+                &thinsp;{'*'}
               </React.Fragment>
             ) : (
               label
diff --git a/packages/mui-material/src/OutlinedInput/OutlinedInput.test.js b/packages/mui-material/src/OutlinedInput/OutlinedInput.test.js
index a40db53e4cc589..cbca44086563f3 100644
--- a/packages/mui-material/src/OutlinedInput/OutlinedInput.test.js
+++ b/packages/mui-material/src/OutlinedInput/OutlinedInput.test.js
@@ -47,7 +47,7 @@ describe('<OutlinedInput />', () => {
       />,
     );
     const notchOutlined = container.querySelector('.notched-outlined legend');
-    expect(notchOutlined).to.have.text('label\xa0*');
+    expect(notchOutlined).to.have.text('label\u2009*');
   });
 
   it('should forward classes to InputBase', () => {
diff --git a/packages/mui-material/src/TextField/TextField.test.js b/packages/mui-material/src/TextField/TextField.test.js
index 2b9e16ac9f749a..8987dcd335089c 100644
--- a/packages/mui-material/src/TextField/TextField.test.js
+++ b/packages/mui-material/src/TextField/TextField.test.js
@@ -111,7 +111,7 @@ describe('<TextField />', () => {
       const [, fakeLabel] = getAllByTestId('label');
       const notch = container.querySelector('.notch legend');
       expect(notch).to.contain(fakeLabel);
-      expect(notch).to.have.text('label\u00a0*');
+      expect(notch).to.have.text('label\u2009*');
     });
 
     it('should set shrink prop on outline from label', () => {
@@ -127,7 +127,7 @@ describe('<TextField />', () => {
       );
 
       const notch = container.querySelector('.notch legend');
-      expect(notch).to.have.text('0\u00a0*');
+      expect(notch).to.have.text('0\u2009*');
     });
 
     it('should not set padding for empty, null or undefined label props', function test() {