diff --git a/composer.json b/composer.json
index d1b2b031..5647262d 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     "phpspec/prophecy": "^1.12.2",
     "phpspec/prophecy-phpunit": "^2.0.1",
     "phpstan/phpstan": "^0.12.82",
-    "phpunit/phpunit": "^9.5.3",
+    "phpunit/phpunit": "^9.5.4",
     "psalm/plugin-phpunit": "^0.15.1",
     "roave/backward-compatibility-check": "^5.0.0",
     "roave/infection-static-analysis-plugin": "^1.7.1",
diff --git a/composer.lock b/composer.lock
index 897218b0..aebdb1e9 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": "dcbb6f4170dcf16f85d1af9b0f7577fa",
+    "content-hash": "db2c74d43ba40afdd853ee40812b14f8",
     "packages": [
         {
             "name": "amphp/amp",
@@ -4174,16 +4174,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "9.5.3",
+            "version": "9.5.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "27241ac75fc37ecf862b6e002bf713b6566cbe41"
+                "reference": "c73c6737305e779771147af66c96ca6a7ed8a741"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/27241ac75fc37ecf862b6e002bf713b6566cbe41",
-                "reference": "27241ac75fc37ecf862b6e002bf713b6566cbe41",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/c73c6737305e779771147af66c96ca6a7ed8a741",
+                "reference": "c73c6737305e779771147af66c96ca6a7ed8a741",
                 "shasum": ""
             },
             "require": {
@@ -4261,7 +4261,7 @@
             ],
             "support": {
                 "issues": "https://github.com/sebastianbergmann/phpunit/issues",
-                "source": "https://github.com/sebastianbergmann/phpunit/tree/9.5.3"
+                "source": "https://github.com/sebastianbergmann/phpunit/tree/9.5.4"
             },
             "funding": [
                 {
@@ -4273,7 +4273,7 @@
                     "type": "github"
                 }
             ],
-            "time": "2021-03-17T07:30:34+00:00"
+            "time": "2021-03-23T07:16:29+00:00"
         },
         {
             "name": "psalm/plugin-phpunit",