diff --git a/composer.json b/composer.json
index ddb841d..fd445b1 100644
--- a/composer.json
+++ b/composer.json
@@ -15,8 +15,7 @@
     "codeinc/psr7-responses": "^2",
     "matthiasmullie/minify": "^1.3",
     "codeinc/media-types": "^1.0",
-    "enshrined/svg-sanitize": "^0.8.2",
-    "ramsey/uuid": "^3.8"
+    "enshrined/svg-sanitize": "^0.8.2"
   },
   "require-dev": {
     "phpunit/phpunit": "^7",
diff --git a/src/AssetsMiddleware.php b/src/AssetsMiddleware.php
index a3d462a..342c307 100644
--- a/src/AssetsMiddleware.php
+++ b/src/AssetsMiddleware.php
@@ -36,7 +36,6 @@
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
-use Ramsey\Uuid\Uuid;
 
 
 /**
@@ -111,7 +110,7 @@ public function addAssetsDirectory(string $directoryPath, string $directoryKey =
         if ($directoryKey !== null && empty($directoryKey)) {
             throw new EmptyDirectoryKeyException($directoryPath);
         }
-        $this->assetsDirectories[$directoryKey ?? Uuid::uuid4()->toString()] = $directoryPath;
+        $this->assetsDirectories[$directoryKey ?? hash('sha1', $directoryPath)] = $directoryPath;
     }
 
     /**