diff --git a/lib/picomatch.js b/lib/picomatch.js
index fbb8b1c..448d354 100644
--- a/lib/picomatch.js
+++ b/lib/picomatch.js
@@ -157,9 +157,9 @@ picomatch.test = (input, regex, options, { glob, posix } = {}) => {
  * @api public
  */
 
-picomatch.matchBase = (input, glob, options) => {
+picomatch.matchBase = (input, glob, options, posix = options && options.windows) => {
   const regex = glob instanceof RegExp ? glob : picomatch.makeRe(glob, options);
-  return regex.test(utils.basename(input));
+  return regex.test(utils.basename(input, { windows: posix }));
 };
 
 /**
diff --git a/test/options.js b/test/options.js
index 8993d18..5d0f98a 100644
--- a/test/options.js
+++ b/test/options.js
@@ -2,7 +2,7 @@
 
 const assert = require('assert');
 const match = require('./support/match');
-const { isMatch } = require('..');
+const { isMatch, matchBase } = require('..');
 
 describe('options', () => {
   describe('options.matchBase', () => {
@@ -15,6 +15,19 @@ describe('options', () => {
       assert.deepStrictEqual(match(['x/y/acb', 'acb/', 'acb/d/e', 'x/y/acb/d'], 'a?b', { matchBase: true, windows: true }), ['x/y/acb', 'acb/']);
     });
 
+    it('should match the basename of backslash-separated paths when `options.windows` is true', () => {
+      assert(isMatch('foo\\bar.js', '*.js', { matchBase: true, windows: true }));
+      assert(isMatch('a\\b\\c\\d.md', '*.md', { matchBase: true, windows: true }));
+      assert(isMatch('a\\b\\c\\foo.md', '*.md', { matchBase: true, windows: true }));
+      assert(isMatch('x\\y\\acb', 'a?b', { matchBase: true, windows: true }));
+      assert(!isMatch('a\\b\\c\\d.md', '*.js', { matchBase: true, windows: true }));
+    });
+
+    it('should pass the `windows` option through `matchBase`', () => {
+      assert(matchBase('foo\\bar.js', '*.js', { windows: true }));
+      assert(matchBase('a\\b\\c\\d.md', '*.md', { windows: true }));
+    });
+
     it('should work with negation patterns', () => {
       assert(isMatch('./x/y.js', '*.js', { matchBase: true, windows: true }));
       assert(!isMatch('./x/y.js', '!*.js', { matchBase: true, windows: true }));