diff --git a/src/Provider/AssetServiceProvider.php b/src/Provider/AssetServiceProvider.php
index <HASH>..<HASH> 100644
--- a/src/Provider/AssetServiceProvider.php
+++ b/src/Provider/AssetServiceProvider.php
@@ -34,11 +34,12 @@ class AssetServiceProvider implements ServiceProviderInterface
 
         $app['asset.file.hash'] = $app->protect(function ($fileName) use ($app) {
             $fullPath = $app['resources']->getPath('root') . '/' . $fileName;
+
             if (is_readable($fullPath)) {
-                return substr(md5($app['asset.salt'] . filemtime($fullPath)), 0, 10);
+                return substr(md5($app['asset.salt'] . (string) filemtime($fullPath, 0, 10)));
+            } elseif (is_readable($fileName)) {
+                return substr(md5($app['asset.salt'] . (string) filemtime($fileName)), 0, 10);
             }
-
-            return substr(md5($app['asset.salt'] . $fileName), 0, 10);
         });
 
         $app['asset.injector'] = $app->share(
Only return a hash if the file can be found