diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 8241598b7c84bc8e5daa983a2bc3b72d675b897f..102bf4903af4ff34f189a0bd22c15afae52b9703 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -1,6 +1,8 @@
 
 Libraries 8.x-3.x, xxxx-xx-xx
 -----------------------------
+#2770983 by tstoeckler: Make Libraries API work on Windows.
+#2770983 by tstoeckler: Allow libraries to be symlinked to their right place.
 #2756265 by rajeshwari10: Replace deprecated usage of SafeMarkup::checkPlain().
 #2742333 by jrockowitz: Fix missing @group in LinePatternDetectorTest
 by tstoeckler: Document plugin alter hooks
diff --git a/src/ExternalLibrary/PhpFile/PhpFileLibrary.php b/src/ExternalLibrary/PhpFile/PhpFileLibrary.php
index da46df3557d55abd10a31df5820a46c29982cbf6..6134849186345dc7158670027436479d52b912f7 100644
--- a/src/ExternalLibrary/PhpFile/PhpFileLibrary.php
+++ b/src/ExternalLibrary/PhpFile/PhpFileLibrary.php
@@ -57,7 +57,7 @@ class PhpFileLibrary extends LibraryBase implements PhpFileLibraryInterface {
 
     $processed_files = [];
     foreach ($this->files as $file) {
-      $processed_files[] = $this->getLocalPath() . DIRECTORY_SEPARATOR . $file;
+      $processed_files[] = $this->getLocalPath() . '/' . $file;
     }
     return $processed_files;
   }
diff --git a/tests/src/Kernel/ExternalLibrary/PhpFile/PhpFileLibraryTest.php b/tests/src/Kernel/ExternalLibrary/PhpFile/PhpFileLibraryTest.php
index 832eda563140fdee10412fc04e6aab33cc50bfd1..10c1d2cfee45cc789d1632925badba861e15391a 100644
--- a/tests/src/Kernel/ExternalLibrary/PhpFile/PhpFileLibraryTest.php
+++ b/tests/src/Kernel/ExternalLibrary/PhpFile/PhpFileLibraryTest.php
@@ -39,7 +39,7 @@ class PhpFileLibraryTest extends LibraryTypeKernelTestBase {
     /** @var \Drupal\libraries\ExternalLibrary\PhpFile\PhpFileLibrary $library */
     $library = $this->getLibrary();
     $this->assertTrue($library->isInstalled());
-    $library_path = $this->modulePath . DIRECTORY_SEPARATOR . 'tests/libraries/test_php_file_library';
+    $library_path = $this->modulePath . '/tests/libraries/test_php_file_library';
     $this->assertEquals($library_path, $library->getLocalPath());
     $this->assertEquals(["$library_path/test_php_file_library.php"], $library->getPhpFiles());
   }