diff --git a/tools/composer.json b/tools/composer.json
index 421e5922..f588bb90 100644
--- a/tools/composer.json
+++ b/tools/composer.json
@@ -3,7 +3,7 @@
     "description": "Aeon PHP Calendar - Tools",
     "require-dev": {
         "phpunit/phpunit": "^9.5",
-        "phpstan/phpstan": "^1.1.2",
+        "phpstan/phpstan": "^2.1.16",
         "infection/infection": "^0.29.10",
         "phpbench/phpbench": "^1.2.6",
         "friendsofphp/php-cs-fixer": "^3.1",
diff --git a/tools/composer.lock b/tools/composer.lock
index e34e4622..94515f9d 100644
--- a/tools/composer.lock
+++ b/tools/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "53321ef7b09ed99fff229ebd1d8b1a32",
+    "content-hash": "f142b20d866b511d17955e1b4ce4d2ec",
     "packages": [],
     "packages-dev": [
         {
@@ -1905,20 +1905,20 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "1.12.16",
+            "version": "2.1.16",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "e0bb5cb78545aae631220735aa706eac633a6be9"
+                "reference": "b8c1cf533cba0c305d91c6ccd23f3dd0566ba5f9"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/e0bb5cb78545aae631220735aa706eac633a6be9",
-                "reference": "e0bb5cb78545aae631220735aa706eac633a6be9",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/b8c1cf533cba0c305d91c6ccd23f3dd0566ba5f9",
+                "reference": "b8c1cf533cba0c305d91c6ccd23f3dd0566ba5f9",
                 "shasum": ""
             },
             "require": {
-                "php": "^7.2|^8.0"
+                "php": "^7.4|^8.0"
             },
             "conflict": {
                 "phpstan/phpstan-shim": "*"
@@ -1959,7 +1959,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2025-01-21T14:50:05+00:00"
+            "time": "2025-05-16T09:40:10+00:00"
         },
         {
             "name": "phpunit/php-code-coverage",