diff --git a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
index a1b3a666138c..8bba20e4a2be 100644
--- a/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
+++ b/src/Symfony/Component/Filesystem/Tests/FilesystemTest.php
@@ -1812,7 +1812,7 @@ public function testReadFile()
     public function testReadNonExistentFile()
     {
         $this->expectException(IOException::class);
-        $this->expectExceptionMessageMatches('#^Failed to read file ".+/Tests/invalid"\\: file_get_contents\\(.+/Tests/invalid\\)\\: Failed to open stream\\: No such file or directory$#');
+        $this->expectExceptionMessageMatches(sprintf('#^Failed to read file ".+%1$sTests/invalid"\\: file_get_contents\\(.+%1$sTests/invalid\\)\\: Failed to open stream\\: No such file or directory$#', preg_quote(\DIRECTORY_SEPARATOR)));
 
         $this->filesystem->readFile(__DIR__.'/invalid');
     }
@@ -1820,7 +1820,7 @@ public function testReadNonExistentFile()
     public function testReadDirectory()
     {
         $this->expectException(IOException::class);
-        $this->expectExceptionMessageMatches('#^Failed to read file ".+/Tests"\\: File is a directory\\.$#');
+        $this->expectExceptionMessageMatches(sprintf('#^Failed to read file ".+%sTests"\\: File is a directory\\.$#', preg_quote(\DIRECTORY_SEPARATOR)));
 
         $this->filesystem->readFile(__DIR__);
     }