diff --git a/.github/workflows/cs.yml b/.github/workflows/cs.yml
index 00b6a01..554bc00 100644
--- a/.github/workflows/cs.yml
+++ b/.github/workflows/cs.yml
@@ -40,10 +40,26 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v4
 
+      - name: Determine the base branch for the file diff
+        id: base_branch
+        env:
+          BASE_REF: ${{ github.base_ref }}
+        run: |
+          if [ "${{ github.event_name }}" == "pull_request" ]; then
+            echo "NAME=$BASE_REF" >> $GITHUB_OUTPUT
+            echo "REF=origin/$BASE_REF" >> $GITHUB_OUTPUT
+          else
+            echo 'NAME=main' >> $GITHUB_OUTPUT
+            echo "REF=origin/main" >> $GITHUB_OUTPUT
+          fi
+
+      - name: Fetch base branch
+        run: git fetch --no-tags --depth=1 origin ${{ steps.base_branch.outputs.NAME }}
+
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: '7.4'
+          php-version: 'latest'
           coverage: none
           tools: cs2pr
 
@@ -60,12 +76,18 @@ jobs:
           # Bust the cache at least once a month - output format: YYYY-MM.
           custom-cache-suffix: $(date -u "+%Y-%m")
 
-      # Check the codestyle of the files.
-      # The results of the CS check will be shown inline in the PR via the CS2PR tool.
+      # Check the codestyle of the files against a threshold of expected errors and warnings.
+      - name: Check PHP code style against the thresholds
+        run: composer check-cs-thresholds
+
+      # Check the codestyle only of the files which were changed in the current branch.
+      # This step will only be executed if the threshold check exited with a failure status.
+      # The results of this CS check will be shown inline in the PR via the CS2PR tool.
       # @link https://github.com/staabm/annotate-pull-request-from-checkstyle/
-      - name: Check PHP code style
+      - name: Check PHP code style for the changes made in the branch only
+        if: ${{ failure() }}
         id: phpcs
-        run: composer check-cs-warnings -- --no-cache --report-full --report-checkstyle=./phpcs-report.xml
+        run: composer check-branch-cs -- ${{ steps.base_branch.outputs.REF }}
 
       - name: Show PHPCS results in PR
         if: ${{ always() && steps.phpcs.outcome == 'failure' }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ac6ef4d..e05c313 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -69,12 +69,9 @@ jobs:
           coverage: ${{ matrix.coverage == true && 'xdebug' || 'none' }}
           tools: cs2pr
 
-      # YoastCS has a minimum PHP requirement of 5.4, so remove it and hard require Parallel Lint.
-      - name: Adjust Composer dependencies (PHP 5.3)
-        if: matrix.php_version == '5.3'
-        run: |
-          composer remove --dev --no-update --no-scripts yoast/yoastcs --no-interaction
-          composer require --dev --no-update --no-scripts php-parallel-lint/php-parallel-lint --no-interaction
+      # YoastCS 3.0 has a PHP 7.2 minimum which conflicts with the requirements of this package.
+      - name: 'Composer: remove YoastCS'
+        run: composer remove --dev yoast/yoastcs --no-update --no-interaction
 
       # Install dependencies and handle caching in one go.
       # @link https://github.com/marketplace/actions/install-php-dependencies-with-composer
diff --git a/.phpcs.xml.dist b/.phpcs.xml.dist
index 5c2d752..570f3b9 100644
--- a/.phpcs.xml.dist
+++ b/.phpcs.xml.dist
@@ -8,7 +8,7 @@
 	<!--
 	#############################################################################
 	COMMAND LINE ARGUMENTS
-	https://github.com/squizlabs/PHP_CodeSniffer/wiki/Annotated-ruleset.xml
+	https://github.com/PHPCSStandards/PHP_CodeSniffer/wiki/Annotated-ruleset.xml
 	#############################################################################
 	-->
 
@@ -39,7 +39,7 @@
 	<rule ref="Yoast">
 		<properties>
 			<!-- Set the minimum supported WP version for all sniff which use it in one go. -->
-			<property name="minimum_supported_version" value="3.0"/>
+			<property name="minimum_wp_version" value="3.0"/>
 
 			<!-- Provide the plugin specific prefixes for all naming related sniffs. -->
 			<property name="prefixes" type="array">
@@ -52,8 +52,12 @@
 		<exclude name="WordPress.NamingConventions.ValidVariableName"/>
 		<exclude name="WordPress.NamingConventions.ValidFunctionName"/>
 
-		<!-- Historically, this library uses camelCaps file names. -->
-		<exclude name="Yoast.Files.FileName"/>
+		<!-- Exclude select "modern PHP" sniffs, which conflict with the minimum supported PHP version of this package. -->
+		<exclude name="SlevomatCodingStandard.Functions.StaticClosure"/><!-- PHP 5.4+ -->
+		<exclude name="SlevomatCodingStandard.Classes.ModernClassNameReference"/><!-- PHP 5.5+ -->
+		<exclude name="Modernize.FunctionCalls.Dirname.Nested"/><!-- PHP 7.0+. -->
+		<exclude name="PSR12.Properties.ConstantVisibility"/><!-- PHP 7.1+. -->
+		<exclude name="SlevomatCodingStandard.TypeHints.NullableTypeForNullDefaultValue"/><!-- PHP 7.1+. -->
 	</rule>
 
 	<!-- Check that variable names are in camelCaps. -->
@@ -83,19 +87,23 @@
 	#############################################################################
 	-->
 
-	<rule ref="Yoast.NamingConventions.NamespaceName">
+	<rule ref="Yoast.Files.FileName">
 		<properties>
-			<!-- Treat the "src" directory as the project root for path to namespace translations. -->
-			<property name="src_directory" type="array">
-				<element value="src"/>
+			<property name="psr4_paths" type="array">
+				<element key="Yoast\WHIP\Tests\\" value="tests/"/>
 			</property>
 		</properties>
+
+		<include-pattern>/tests/*\.php</include-pattern>
 	</rule>
 
-	<rule ref="Yoast.Files.TestDoubles">
+	<rule ref="Yoast.NamingConventions.NamespaceName">
 		<properties>
-			<property name="doubles_path" type="array">
-				<element value="/tests/Unit/Doubles"/>
+			<property name="src_directory" type="array">
+				<element value="src"/>
+			</property>
+			<property name="psr4_paths" type="array">
+				<element key="Yoast\WHIP\Tests\\" value="tests/"/>
 			</property>
 		</properties>
 	</rule>
@@ -118,15 +126,24 @@
 		<exclude-pattern>/src/facades/wordpress\.php$</exclude-pattern>
 	</rule>
 
+	<!-- The variable parameters passed to the WHIP exceptions are mostly used to retrieve
+		 the _type_ of the variable. Additionally, we may not be in a WP context. -->
+	<rule ref="WordPress.Security.EscapeOutput.ExceptionNotEscaped">
+		<severity>0</severity>
+	</rule>
+
+	<rule ref="Yoast.Files.FileName.InvalidFunctionsFileName">
+		<exclude-pattern>/tests/Unit/Doubles/WPCoreFunctionsMock\.php$</exclude-pattern>
+	</rule>
 
 	<!--
 	#############################################################################
 	TEMPORARY TWEAK
-	YoastCS demands short arrays, but the WHIP module still supports PHP 5.2.
+	YoastCS demands short arrays (PHP 5.4), but the WHIP module still supports PHP 5.3.
 	#############################################################################
 	-->
 
-	<rule ref="Generic.Arrays.DisallowShortArraySyntax">
+	<rule ref="Universal.Arrays.DisallowShortArraySyntax">
 		<severity>5</severity>
 	</rule>
 	<rule ref="Generic.Arrays.DisallowLongArraySyntax">
@@ -154,12 +171,4 @@
 		<exclude-pattern>/src/Whip_Host\.php$</exclude-pattern>
 	</rule>
 
-	<!-- The below two issues will likely be fixed in YoastCS 3.0, after which these excludes can be removed. -->
-	<rule ref="Yoast.Commenting.FileComment.Unnecessary">
-		<exclude-pattern>/tests/Unit/bootstrap\.php$</exclude-pattern>
-	</rule>
-	<rule ref="Yoast.NamingConventions.ObjectNameDepth.MaxExceeded">
-		<exclude-pattern>/tests/Unit/WPMessageDismissListenerTest\.php$</exclude-pattern>
-	</rule>
-
 </ruleset>
diff --git a/composer.json b/composer.json
index 78e440c..c407e48 100644
--- a/composer.json
+++ b/composer.json
@@ -19,9 +19,11 @@
 		"php": ">=5.3"
 	},
 	"require-dev": {
+		"php-parallel-lint/php-console-highlighter": "^1.0.0",
+		"php-parallel-lint/php-parallel-lint": "^1.3.2",
 		"phpunit/phpunit": "^4.8.36 || ^5.7.21 || ^6.0 || ^7.0 || ^8.0 || ^9.0",
 		"roave/security-advisories": "dev-master",
-		"yoast/yoastcs": "^2.3.0"
+		"yoast/yoastcs": "^3.0"
 	},
 	"minimum-stability": "dev",
 	"prefer-stable": true,
@@ -54,7 +56,7 @@
 			"Yoast\\WHIP\\Config\\Composer\\Actions::check_coding_standards"
 		],
 		"check-cs-thresholds": [
-			"@putenv YOASTCS_THRESHOLD_ERRORS=0",
+			"@putenv YOASTCS_THRESHOLD_ERRORS=8",
 			"@putenv YOASTCS_THRESHOLD_WARNINGS=0",
 			"Yoast\\WHIP\\Config\\Composer\\Actions::check_cs_thresholds"
 		],
diff --git a/config/composer/actions.php b/config/composer/actions.php
index 5e2d730..23cb96a 100644
--- a/config/composer/actions.php
+++ b/config/composer/actions.php
@@ -18,6 +18,8 @@ class Actions {
 	 * Provides a coding standards option choice.
 	 *
 	 * @param Event $event Composer event.
+	 *
+	 * @return void
 	 */
 	public static function check_coding_standards( Event $event ) {
 		$io = $event->getIO();
diff --git a/tests/Unit/WPMessageDismissListenerTest.php b/tests/Unit/WPMessageDismissListenerTest.php
index c99b4b0..00ff2ae 100644
--- a/tests/Unit/WPMessageDismissListenerTest.php
+++ b/tests/Unit/WPMessageDismissListenerTest.php
@@ -8,6 +8,8 @@
  * Message Dismiss Listener unit tests.
  *
  * @coversDefaultClass Whip_WPMessageDismissListener
+ *
+ * @phpcs:disable Yoast.NamingConventions.ObjectNameDepth.MaxExceeded -- Acronym throws the count off.
  */
 final class WPMessageDismissListenerTest extends TestCase {