diff --git a/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php b/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
index 12ed37b..240c9e0 100644
--- a/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
+++ b/core/modules/file/tests/src/Kernel/Migrate/d7/MigrateFileTest.php
@@ -36,7 +36,7 @@ protected function setUp() {
     // Set the source plugin's source_base_path configuration value, which
     // would normally be set by the user running the migration.
     $source = $migration->getSourceConfiguration();
-    $source['constants']['source_base_path'] = $fs->realpath('public://') . '/';
+    $source['constants']['source_base_path'] = $fs->realpath('public://');
     $migration->set('source', $source);
     $this->executeMigration($migration);
   }