diff --git a/composer.json b/composer.json
index 58788c4..6c70e8f 100644
--- a/composer.json
+++ b/composer.json
@@ -38,6 +38,6 @@
     },
     "require-dev": {
         "phpunit/phpunit": "~5.7",
-        "mikey179/vfsStream": "^1.6"
+        "mikey179/vfsstream": "^1.6"
     }
 }