diff --git a/lib/rouge/lexers/javascript.rb b/lib/rouge/lexers/javascript.rb
index db6546fe4e..8b12e468e3 100644
--- a/lib/rouge/lexers/javascript.rb
+++ b/lib/rouge/lexers/javascript.rb
@@ -15,7 +15,7 @@ class Javascript < RegexLexer
 
       tag 'javascript'
       aliases 'js'
-      filenames '*.js', '*.mjs'
+      filenames '*.cjs', '*.js', '*.mjs'
       mimetypes 'application/javascript', 'application/x-javascript',
                 'text/javascript', 'text/x-javascript'
 
diff --git a/spec/lexers/javascript_spec.rb b/spec/lexers/javascript_spec.rb
index db059a8024..5afe694d4a 100644
--- a/spec/lexers/javascript_spec.rb
+++ b/spec/lexers/javascript_spec.rb
@@ -17,7 +17,9 @@
     include Support::Guessing
 
     it 'guesses by filename' do
+      assert_guess :filename => 'foo.cjs'
       assert_guess :filename => 'foo.js'
+      assert_guess :filename => 'foo.mjs'
     end
 
     it 'guesses by mimetype' do