diff --git a/composer.json b/composer.json
index b26fe4a..d610968 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
   "require-dev": {
     "phpunit/phpunit": "^8.5 || ^9.0",
     "php-coveralls/php-coveralls": "^2.2",
-    "vimeo/psalm": "5.15.0"
+    "vimeo/psalm": "5.21.1"
   },
   "autoload": {
     "psr-4": {