diff --git a/src/Symfony/Component/Filesystem/Filesystem.php b/src/Symfony/Component/Filesystem/Filesystem.php
index a8701533cbd38..2188c96bf2600 100644
--- a/src/Symfony/Component/Filesystem/Filesystem.php
+++ b/src/Symfony/Component/Filesystem/Filesystem.php
@@ -456,15 +456,18 @@ public function makePathRelative($endPath, $startPath)
         }
 
         $stripDriveLetter = function ($path) {
-            if (\strlen($path) > 2 && ':' === $path[1] && '/' === $path[2] && ctype_alpha($path[0])) {
-                return substr($path, 2);
-            }
-
-            return $path;
+            return (\strlen($path) > 2 && ':' === $path[1] && '/' === $path[2] && ctype_alpha($path[0]))
+                ? [substr($path, 2), $path[0]]
+                : [$path, null];
         };
 
-        $endPath = $stripDriveLetter($endPath);
-        $startPath = $stripDriveLetter($startPath);
+        list($endPath, $endDriveLetter) = $stripDriveLetter($endPath);
+        list($startPath, $startDriveLetter) = $stripDriveLetter($startPath);
+
+        if ($endDriveLetter && $startDriveLetter && $endDriveLetter <> $startDriveLetter) {
+            // Different drives
+            return $endDriveLetter.':'.$endPath;
+        }
 
         // Split the paths into arrays
         $startPathArr = explode('/', trim($startPath, '/'));
diff --git a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
index e9e7784a3af40..a3d8d98dfe870 100644
--- a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
+++ b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
@@ -1115,6 +1115,7 @@ public function providePathsForMakePathRelative()
             ['C:/aa/bb/../../cc', 'C:/aa/../dd/..', 'cc/'],
             ['C:/../aa/bb/cc', 'C:/aa/dd/..', 'bb/cc/'],
             ['C:/../../aa/../bb/cc', 'C:/aa/dd/..', '../bb/cc/'],
+            ['D:/aa/bb', 'C:/aa', 'D:/aa/bb'],
         ];
 
         if ('\\' === \DIRECTORY_SEPARATOR) {