diff --git a/composer.json b/composer.json
index e0da2b8..69617f6 100644
--- a/composer.json
+++ b/composer.json
@@ -22,7 +22,7 @@
   },
   "require-dev": {
     "phpunit/phpunit": "6.*",
-    "phpstan/phpstan": "^0.10.5"
+    "phpstan/phpstan": "0.12.99"
   },
   "autoload": {
     "psr-4": {