diff --git a/composer.json b/composer.json
index 4f25be4..f3701fd 100644
--- a/composer.json
+++ b/composer.json
@@ -43,7 +43,7 @@
     "amphp/phpunit-util": "^3.0",
     "ergebnis/phpstan-rules": "^2.1",
     "lendable/clock": "^2.3",
-    "php-cs-fixer/shim": "^v3.39.1",
+    "php-cs-fixer/shim": "^v3.40.0",
     "php-standard-library/phpstan-extension": "^1.0",
     "phpstan/phpstan": "^1.10.44",
     "phpstan/phpstan-deprecation-rules": "^1.1.4",
diff --git a/composer.lock b/composer.lock
index fec8fb3..795169e 100644
--- a/composer.lock
+++ b/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": "d3a025cf141bfe1ed9eca6d9e2509b08",
+    "content-hash": "913a554d1f60b8d5b746cade0b294600",
     "packages": [
         {
             "name": "amphp/amp",
@@ -2543,16 +2543,16 @@
         },
         {
             "name": "php-cs-fixer/shim",
-            "version": "v3.39.1",
+            "version": "v3.40.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/PHP-CS-Fixer/shim.git",
-                "reference": "5650ccad60679544eda1a6305619ca074f0fa95a"
+                "reference": "4c063eff281b1e3a73c33c0d5c39e8e2b766464e"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/PHP-CS-Fixer/shim/zipball/5650ccad60679544eda1a6305619ca074f0fa95a",
-                "reference": "5650ccad60679544eda1a6305619ca074f0fa95a",
+                "url": "https://api.github.com/repos/PHP-CS-Fixer/shim/zipball/4c063eff281b1e3a73c33c0d5c39e8e2b766464e",
+                "reference": "4c063eff281b1e3a73c33c0d5c39e8e2b766464e",
                 "shasum": ""
             },
             "require": {
@@ -2589,9 +2589,9 @@
             "description": "A tool to automatically fix PHP code style",
             "support": {
                 "issues": "https://github.com/PHP-CS-Fixer/shim/issues",
-                "source": "https://github.com/PHP-CS-Fixer/shim/tree/v3.39.1"
+                "source": "https://github.com/PHP-CS-Fixer/shim/tree/v3.40.0"
             },
-            "time": "2023-11-24T22:59:27+00:00"
+            "time": "2023-11-26T09:26:25+00:00"
         },
         {
             "name": "php-standard-library/phpstan-extension",