diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 4750408173ec07..ab4746ee1d5049 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -429,8 +429,6 @@ def _default_mime_types():
     # Make sure the entry with the preferred file extension for a particular mime type
     # appears before any others of the same mimetype.
     types_map = _types_map_default = {
-        '.js'     : 'application/javascript',
-        '.mjs'    : 'application/javascript',
         '.json'   : 'application/json',
         '.webmanifest': 'application/manifest+json',
         '.doc'    : 'application/msword',
@@ -549,6 +547,8 @@ def _default_mime_types():
         '.csv'    : 'text/csv',
         '.html'   : 'text/html',
         '.htm'    : 'text/html',
+        '.js'     : 'text/javascript',
+        '.mjs'    : 'text/javascript',
         '.n3'     : 'text/n3',
         '.txt'    : 'text/plain',
         '.bat'    : 'text/plain',
diff --git a/Lib/test/test_mimetypes.py b/Lib/test/test_mimetypes.py
index 4098a22644092f..ebda5678cf9a0a 100644
--- a/Lib/test/test_mimetypes.py
+++ b/Lib/test/test_mimetypes.py
@@ -136,6 +136,9 @@ def test_guess_all_types(self):
         all.append('.no-such-ext')
         all = self.db.guess_all_extensions('test-type')
         self.assertNotIn('.no-such-ext', all)
+        all = self.db.guess_all_extensions('text/javascript', strict=True)
+        self.assertTrue(set(all) >= {'.js', '.mjs'})
+        self.assertEqual(len(set(all)), len(all))
 
     def test_encoding(self):
         getpreferredencoding = locale.getpreferredencoding
diff --git a/Misc/NEWS.d/next/Library/2022-01-21-15-58-09.bpo-34875.Y5vWXU.rst b/Misc/NEWS.d/next/Library/2022-01-21-15-58-09.bpo-34875.Y5vWXU.rst
new file mode 100644
index 00000000000000..b7cb26210acf25
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-01-21-15-58-09.bpo-34875.Y5vWXU.rst
@@ -0,0 +1 @@
+Change '.js' and '.mjs' mime to 'text/javascript'