diff --git a/composer.json b/composer.json
index b71ab0f..17ad39f 100644
--- a/composer.json
+++ b/composer.json
@@ -37,7 +37,7 @@
     "d3/modcfg": "^5.3.2.000"
   },
   "require-dev": {
-    "mikey179/vfsStream": "^1.4"
+    "mikey179/vfsstream": "^1.4"
   },
   "autoload": {
     "psr-4": {