diff --git a/composer.json b/composer.json
index 5263b968..c709a0c5 100644
--- a/composer.json
+++ b/composer.json
@@ -36,9 +36,9 @@
     "phpstan/phpstan-phpunit": "~0.12.17",
     "phpstan/phpstan-strict-rules": "~0.12.9",
     "phpunit/phpunit": "^8.5.14",
-    "psalm/plugin-phpunit": "~0.12.2",
+    "psalm/plugin-phpunit": "~0.15.0",
     "symfony/filesystem": "^5.1.8",
-    "vimeo/psalm": "^3.18.2"
+    "vimeo/psalm": "^4.4.1"
   },
   "config": {
     "platform": {
diff --git a/composer.lock b/composer.lock
index 3e800e62..20c646f8 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": "fef9286baf0cc8372af2b576a27ef388",
+    "content-hash": "a4b217c9e5d30cfbf8fba172257ddc62",
     "packages": [
         {
             "name": "ergebnis/json-normalizer",
@@ -2860,30 +2860,34 @@
         },
         {
             "name": "psalm/plugin-phpunit",
-            "version": "0.12.2",
+            "version": "0.15.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/psalm/psalm-plugin-phpunit.git",
-                "reference": "85ee5a080a5281e63085d933b30a06b1b1680758"
+                "reference": "30ca25ce069bf4943c36e59b7df6954f6af05e64"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/psalm/psalm-plugin-phpunit/zipball/85ee5a080a5281e63085d933b30a06b1b1680758",
-                "reference": "85ee5a080a5281e63085d933b30a06b1b1680758",
+                "url": "https://api.github.com/repos/psalm/psalm-plugin-phpunit/zipball/30ca25ce069bf4943c36e59b7df6954f6af05e64",
+                "reference": "30ca25ce069bf4943c36e59b7df6954f6af05e64",
                 "shasum": ""
             },
             "require": {
                 "composer/package-versions-deprecated": "^1.10",
                 "composer/semver": "^1.4 || ^2.0 || ^3.0",
                 "ext-simplexml": "*",
-                "php": "^7.1.3 || ^8.0",
-                "phpunit/phpunit": "^7.5 || ^8.0 || ^9.0",
-                "vimeo/psalm": "^3.6.2 || dev-master || dev-4.x"
+                "php": "^7.1 || ^8.0",
+                "vimeo/psalm": "dev-master || dev-4.x || ^4.0"
+            },
+            "conflict": {
+                "phpunit/phpunit": "<7.5"
             },
             "require-dev": {
                 "codeception/codeception": "^4.0.3",
+                "php": "^7.3 || ^8.0",
+                "phpunit/phpunit": "^7.5 || ^8.0 || ^9.0",
                 "squizlabs/php_codesniffer": "^3.3.1",
-                "weirdan/codeception-psalm-module": "^0.7.1",
+                "weirdan/codeception-psalm-module": "^0.11.0",
                 "weirdan/prophecy-shim": "^1.0 || ^2.0"
             },
             "type": "psalm-plugin",
@@ -2908,7 +2912,11 @@
                 }
             ],
             "description": "Psalm plugin for PHPUnit",
-            "time": "2020-09-28T17:25:39+00:00"
+            "support": {
+                "issues": "https://github.com/psalm/psalm-plugin-phpunit/issues",
+                "source": "https://github.com/psalm/psalm-plugin-phpunit/tree/0.15.1"
+            },
+            "time": "2021-01-23T00:19:07+00:00"
         },
         {
             "name": "psr/container",
@@ -5309,16 +5317,16 @@
         },
         {
             "name": "vimeo/psalm",
-            "version": "3.18.2",
+            "version": "4.4.1",
             "source": {
                 "type": "git",
                 "url": "https://github.com/vimeo/psalm.git",
-                "reference": "19aa905f7c3c7350569999a93c40ae91ae4e1626"
+                "reference": "9fd7a7d885b3a216cff8dec9d8c21a132f275224"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/vimeo/psalm/zipball/19aa905f7c3c7350569999a93c40ae91ae4e1626",
-                "reference": "19aa905f7c3c7350569999a93c40ae91ae4e1626",
+                "url": "https://api.github.com/repos/vimeo/psalm/zipball/9fd7a7d885b3a216cff8dec9d8c21a132f275224",
+                "reference": "9fd7a7d885b3a216cff8dec9d8c21a132f275224",
                 "shasum": ""
             },
             "require": {
@@ -5337,12 +5345,11 @@
                 "felixfbecker/advanced-json-rpc": "^3.0.3",
                 "felixfbecker/language-server-protocol": "^1.4",
                 "netresearch/jsonmapper": "^1.0 || ^2.0 || ^3.0",
-                "nikic/php-parser": "4.3.* || 4.4.* || 4.5.* || 4.6.* || ^4.8",
+                "nikic/php-parser": "^4.10.1",
                 "openlss/lib-array2xml": "^1.0",
-                "php": "^7.1.3|^8",
+                "php": "^7.1|^8",
                 "sebastian/diff": "^3.0 || ^4.0",
                 "symfony/console": "^3.4.17 || ^4.1.6 || ^5.0",
-                "webmozart/glob": "^4.1",
                 "webmozart/path-util": "^2.3"
             },
             "provide": {
@@ -5351,14 +5358,14 @@
             "require-dev": {
                 "amphp/amp": "^2.4.2",
                 "bamarni/composer-bin-plugin": "^1.2",
-                "brianium/paratest": "^4.0.0",
+                "brianium/paratest": "^4.0||^6.0",
                 "ext-curl": "*",
-                "phpdocumentor/reflection-docblock": "^4.3.4 || ^5",
-                "phpmyadmin/sql-parser": "5.1.0",
+                "phpdocumentor/reflection-docblock": "^5",
+                "phpmyadmin/sql-parser": "5.1.0||dev-master",
                 "phpspec/prophecy": ">=1.9.0",
-                "phpunit/phpunit": "^7.5.16 || ^8.5 || ^9.0",
-                "psalm/plugin-phpunit": "^0.11",
-                "slevomat/coding-standard": "^5.0",
+                "phpunit/phpunit": "^9.0",
+                "psalm/plugin-phpunit": "^0.13",
+                "slevomat/coding-standard": "^6.3.11",
                 "squizlabs/php_codesniffer": "^3.5",
                 "symfony/process": "^4.3",
                 "weirdan/prophecy-shim": "^1.0 || ^2.0"
@@ -5376,7 +5383,8 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "3.x-dev",
+                    "dev-master": "4.x-dev",
+                    "dev-3.x": "3.x-dev",
                     "dev-2.x": "2.x-dev",
                     "dev-1.x": "1.x-dev"
                 }
@@ -5405,7 +5413,11 @@
                 "inspection",
                 "php"
             ],
-            "time": "2020-10-20T13:48:22+00:00"
+            "support": {
+                "issues": "https://github.com/vimeo/psalm/issues",
+                "source": "https://github.com/vimeo/psalm/tree/4.4.1"
+            },
+            "time": "2021-01-14T21:44:29+00:00"
         },
         {
             "name": "webmozart/assert",
@@ -5456,53 +5468,6 @@
             ],
             "time": "2020-07-08T17:02:28+00:00"
         },
-        {
-            "name": "webmozart/glob",
-            "version": "4.1.0",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/webmozarts/glob.git",
-                "reference": "3cbf63d4973cf9d780b93d2da8eec7e4a9e63bbe"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/webmozarts/glob/zipball/3cbf63d4973cf9d780b93d2da8eec7e4a9e63bbe",
-                "reference": "3cbf63d4973cf9d780b93d2da8eec7e4a9e63bbe",
-                "shasum": ""
-            },
-            "require": {
-                "php": "^5.3.3|^7.0",
-                "webmozart/path-util": "^2.2"
-            },
-            "require-dev": {
-                "phpunit/phpunit": "^4.6",
-                "sebastian/version": "^1.0.1",
-                "symfony/filesystem": "^2.5"
-            },
-            "type": "library",
-            "extra": {
-                "branch-alias": {
-                    "dev-master": "4.1-dev"
-                }
-            },
-            "autoload": {
-                "psr-4": {
-                    "Webmozart\\Glob\\": "src/"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Bernhard Schussek",
-                    "email": "bschussek@gmail.com"
-                }
-            ],
-            "description": "A PHP implementation of Ant's glob.",
-            "time": "2015-12-29T11:14:33+00:00"
-        },
         {
             "name": "webmozart/path-util",
             "version": "2.3.0",
@@ -5563,5 +5528,5 @@
     "platform-overrides": {
         "php": "7.2.33"
     },
-    "plugin-api-version": "1.1.0"
+    "plugin-api-version": "2.0.0"
 }
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 2c7a2f96..a988b628 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<files psalm-version="3.18.2@19aa905f7c3c7350569999a93c40ae91ae4e1626">
-  <file src="src/Application.php">
-    <PropertyNotSetInConstructor occurrences="1">
-      <code>Application</code>
-    </PropertyNotSetInConstructor>
-  </file>
+<files psalm-version="4.4.1@9fd7a7d885b3a216cff8dec9d8c21a132f275224">
   <file src="src/Command/NormalizeCommand.php">
     <MissingPropertyType occurrences="4">
       <code>$differ</code>
@@ -56,6 +51,12 @@
       <code>$composerFile</code>
       <code>$composerFile</code>
     </PossiblyInvalidArgument>
+    <PossiblyInvalidCast occurrences="4">
+      <code>$composerFile</code>
+      <code>$composerFile</code>
+      <code>$composerFile</code>
+      <code>$composerFile</code>
+    </PossiblyInvalidCast>
   </file>
   <file src="test/Integration/Command/NormalizeCommand/AbstractTestCase.php">
     <MixedArrayAccess occurrences="1">