diff --git a/tests/Composer/Test/Util/FilesystemTest.php b/tests/Composer/Test/Util/FilesystemTest.php
index 37e9f1129..d1459169a 100644
--- a/tests/Composer/Test/Util/FilesystemTest.php
+++ b/tests/Composer/Test/Util/FilesystemTest.php
@@ -73,9 +73,11 @@ class FilesystemTest extends TestCase
             array('/foo/bar', '/foo/bar', "./", true),
             array('/foo/bar', '/foo/baz', "../baz", true),
             array('/foo/bar/', '/foo/baz', "../baz", true),
+            array('C:/foo/bar/', 'c:/foo/baz', "../baz", true),
             array('/foo/bin/run', '/foo/vendor/acme/bin/run', "../vendor/acme/bin/run"),
             array('/foo/bin/run', '/bar/bin/run', "/bar/bin/run"),
             array('/foo/bin/run', '/bar/bin/run', "/bar/bin/run", true),
+            array('c:/foo/bin/run', 'd:/bar/bin/run', "d:/bar/bin/run", true),
             array('c:/bin/run', 'c:/vendor/acme/bin/run', "../vendor/acme/bin/run"),
             array('c:\\bin\\run', 'c:/vendor/acme/bin/run', "../vendor/acme/bin/run"),
             array('c:/bin/run', 'd:/vendor/acme/bin/run', "d:/vendor/acme/bin/run"),
@@ -85,6 +87,7 @@ class FilesystemTest extends TestCase
             array('C:/Temp/test/sub', 'C:\Temp', "../"),
             array('/tmp/test/sub', '/tmp', "../"),
             array('/tmp/test/sub', '/tmp', "../../", true),
+            array('c:/tmp/test/sub', 'c:/tmp', "../../", true),
             array('/tmp', '/tmp/test', "test"),
             array('C:/Temp', 'C:\Temp\test', "test"),
             array('C:/Temp', 'c:\Temp\test', "test"),