diff --git a/composer.json b/composer.json
index e30870b..cd06358 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     }
   },
   "require-dev": {
-    "phpunit/phpunit": "^5.0",
+    "phpunit/phpunit": "^4.0",
     "slim/slim": "^3.0"
   }
 }
\ No newline at end of file