diff --git a/composer.json b/composer.json
index 039e86c565d9eee169c57a524fd4be4bef569d6d..b5715f40e28bfd2700b6d75e18586e27587af16d 100644
--- a/composer.json
+++ b/composer.json
@@ -26,7 +26,7 @@
         "phpunit/phpunit": "^9.5",
         "phpspec/prophecy-phpunit": "^2",
         "phpstan/extension-installer": "^1.1",
-        "phpstan/phpstan": "^1.9.3",
+        "phpstan/phpstan": "^1.9.9",
         "symfony/css-selector": "^6.2",
         "symfony/phpunit-bridge": "^6.2",
         "symfony/var-dumper": "^6.2",
diff --git a/composer.lock b/composer.lock
index 7601971d6ff1ef6b26acc4cee282b6d831c5e1b5..f8481108acdf20982998c2f69aa8d182f8672511 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": "e6addf00588106d8ec7218b137c26c1c",
+    "content-hash": "85fce9014bf3bc99add14de1104ac465",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -5914,16 +5914,16 @@
         },
         {
             "name": "phpstan/phpstan",
-            "version": "1.9.3",
+            "version": "1.9.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/phpstan/phpstan.git",
-                "reference": "709999b91448d4f2bb07daffffedc889b33e461c"
+                "reference": "f68d7cc3d0638a01bc6321cb826e4cae7fa6884d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/709999b91448d4f2bb07daffffedc889b33e461c",
-                "reference": "709999b91448d4f2bb07daffffedc889b33e461c",
+                "url": "https://api.github.com/repos/phpstan/phpstan/zipball/f68d7cc3d0638a01bc6321cb826e4cae7fa6884d",
+                "reference": "f68d7cc3d0638a01bc6321cb826e4cae7fa6884d",
                 "shasum": ""
             },
             "require": {
@@ -5953,7 +5953,7 @@
             ],
             "support": {
                 "issues": "https://github.com/phpstan/phpstan/issues",
-                "source": "https://github.com/phpstan/phpstan/tree/1.9.3"
+                "source": "https://github.com/phpstan/phpstan/tree/1.9.9"
             },
             "funding": [
                 {
@@ -5969,7 +5969,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2022-12-13T10:28:10+00:00"
+            "time": "2023-01-11T14:39:22+00:00"
         },
         {
             "name": "phpunit/php-code-coverage",
diff --git a/composer/Metapackage/DevDependencies/composer.json b/composer/Metapackage/DevDependencies/composer.json
index d75151599b18663d3f9db24c9a211ec51644be43..fbaa88b877992cfcef830713193ce18448b4f240 100644
--- a/composer/Metapackage/DevDependencies/composer.json
+++ b/composer/Metapackage/DevDependencies/composer.json
@@ -18,7 +18,7 @@
         "mikey179/vfsstream": "^1.6.11",
         "phpspec/prophecy-phpunit": "^2",
         "phpstan/extension-installer": "^1.1",
-        "phpstan/phpstan": "^1.9.3",
+        "phpstan/phpstan": "^1.9.9",
         "phpunit/phpunit": "^9.5",
         "symfony/browser-kit": "^6.2",
         "symfony/css-selector": "^6.2",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index da385b5b52ce204c7c0ba65d1b1f407a9a37021c..10fb8de2d24eebd8cbdc64d40aeaf855261396f0 100644
--- a/composer/Metapackage/PinnedDevDependencies/composer.json
+++ b/composer/Metapackage/PinnedDevDependencies/composer.json
@@ -36,7 +36,7 @@
         "phpspec/prophecy-phpunit": "v2.0.1",
         "phpstan/extension-installer": "1.2.0",
         "phpstan/phpdoc-parser": "1.13.1",
-        "phpstan/phpstan": "1.9.3",
+        "phpstan/phpstan": "1.9.9",
         "phpunit/php-code-coverage": "9.2.19",
         "phpunit/php-file-iterator": "3.0.6",
         "phpunit/php-invoker": "3.1.1",
diff --git a/core/phpstan-baseline.neon b/core/phpstan-baseline.neon
index 16aba07556b9d64fc1a8f9870dd949dc75d46b63..779ddbc2dd1b841794767da4376cd7eff35eddb0 100644
--- a/core/phpstan-baseline.neon
+++ b/core/phpstan-baseline.neon
@@ -185,11 +185,6 @@ parameters:
 			count: 1
 			path: lib/Drupal/Component/Gettext/PoStreamReader.php
 
-		-
-			message: "#^Variable \\$rgb might not be defined\\.$#"
-			count: 1
-			path: lib/Drupal/Component/Utility/Color.php
-
 		-
 			message: "#^Variable \\$permission might not be defined\\.$#"
 			count: 1
@@ -2220,11 +2215,6 @@ parameters:
 			count: 5
 			path: modules/system/tests/src/Functional/FileTransfer/TestFileTransfer.php
 
-		-
-			message: "#^Variable \\$checked might not be defined\\.$#"
-			count: 1
-			path: modules/system/tests/src/Functional/Form/CheckboxTest.php
-
 		-
 			message: "#^Variable \\$form_output in empty\\(\\) always exists and is not falsy\\.$#"
 			count: 2