diff --git a/tests/Core/Fixer/GenerateDiffTest.php b/tests/Core/Fixer/GenerateDiffTest.php
index 9b3f115e40..b7902bbe61 100644
--- a/tests/Core/Fixer/GenerateDiffTest.php
+++ b/tests/Core/Fixer/GenerateDiffTest.php
@@ -21,6 +21,7 @@
  * test running the fixer itself, nor generating a diff based on a fixer run.
  *
  * @covers PHP_CodeSniffer\Fixer::generateDiff
+ * @group  Windows
  */
 final class GenerateDiffTest extends TestCase
 {