diff --git a/src/test/java/com/google/devtools/build/lib/vfs/PathFragmentWindowsTest.java b/src/test/java/com/google/devtools/build/lib/vfs/PathFragmentWindowsTest.java
index a8dc24fa1870b5..14ef5c44dfffa5 100644
--- a/src/test/java/com/google/devtools/build/lib/vfs/PathFragmentWindowsTest.java
+++ b/src/test/java/com/google/devtools/build/lib/vfs/PathFragmentWindowsTest.java
@@ -193,6 +193,9 @@ public void testBasenameWindows() throws Exception {
     assertThat(create("C:/foo").getBaseName()).isEqualTo("foo");
     // Never return the drive name as a basename.
     assertThat(create("C:/").getBaseName()).isEmpty();
+    // Mix usage of Windows and Unix separator is valid
+    assertThat(create("C:/foo\\bar").getBaseName()).isEqualTo("bar");
+    assertThat(create("C:\\foo\\bar/baz").getBaseName()).isEqualTo("baz");
   }
 
   @Test