diff --git a/.github/workflows/docker-hub.yml b/.github/workflows/docker-hub.yml
index 20a40a6..47e5cc2 100644
--- a/.github/workflows/docker-hub.yml
+++ b/.github/workflows/docker-hub.yml
@@ -73,69 +73,6 @@ jobs:
           docker images
           docker push $PACKAGE_REGISTRY/php:latest$PR_TAG
 
-  build-phpunit-images:
-    name: PHPUnit on PHP ${{ matrix.php }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        php: [ '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4' ]
-
-    env:
-      PHP_VERSION: ${{ matrix.php }}
-      PHP_LATEST: '8.2'
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG images/$PHP_VERSION/phpunit
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG
-
-      - name: Tag and push image as latest
-        if: ${{ env.PHP_LATEST == env.PHP_VERSION }}
-        run: |
-          docker image tag $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-          docker push $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-
-  build-specific-phpunit-images:
-    name: PHPUnit ${{ matrix.phpunit }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        phpunit: [ '8-php-7.2', '7-php-7.2', '6-php-7.2', '9-php-7.3', '8-php-7.3', '7-php-7.3', '6-php-7.3', '9-php-7.4', '8-php-7.4', '7-php-7.4', '9-php-8.0', '8-php-8.0', '9-php-8.1', '8-php-8.1', '9-php-8.2', '8-php-8.2', '9-php-8.3' ]
-
-    env:
-      PHPUNIT_VERSION: ${{ matrix.phpunit }}
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG images/phpunit/$PHPUNIT_VERSION
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG
-
   build-cli-images:
     name: CLI on PHP ${{ matrix.php }}
     runs-on: ubuntu-latest
diff --git a/.github/workflows/github-container-registry.yml b/.github/workflows/github-container-registry.yml
index 335264b..7f5c6f6 100644
--- a/.github/workflows/github-container-registry.yml
+++ b/.github/workflows/github-container-registry.yml
@@ -82,69 +82,6 @@ jobs:
           docker images
           docker push $PACKAGE_REGISTRY/php:latest$PR_TAG
 
-  build-phpunit-images:
-    name: PHPUnit on PHP ${{ matrix.php }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        php: [ '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4' ]
-
-    env:
-      PHP_VERSION: ${{ matrix.php }}
-      PHP_LATEST: '8.2'
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG images/$PHP_VERSION/phpunit
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG
-
-      - name: Tag and push image as latest
-        if: ${{ env.PHP_LATEST == env.PHP_VERSION }}
-        run: |
-          docker image tag $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-          docker push $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-
-  build-specific-phpunit-images:
-    name: PHPUnit ${{ matrix.phpunit }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        phpunit: [ '8-php-7.2', '7-php-7.2', '6-php-7.2', '9-php-7.3', '8-php-7.3', '7-php-7.3', '6-php-7.3', '9-php-7.4', '8-php-7.4', '7-php-7.4', '9-php-8.0', '8-php-8.0', '9-php-8.1', '8-php-8.1', '9-php-8.2', '8-php-8.2', '9-php-8.3' ]
-
-    env:
-      PHPUNIT_VERSION: ${{ matrix.phpunit }}
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG images/phpunit/$PHPUNIT_VERSION
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG
-
   build-cli-images:
     name: CLI on PHP ${{ matrix.php }}
     runs-on: ubuntu-latest
diff --git a/templates/workflow.yml-template b/templates/workflow.yml-template
index f67ddb1..f0592e1 100644
--- a/templates/workflow.yml-template
+++ b/templates/workflow.yml-template
@@ -100,69 +100,6 @@ jobs:
           docker images
           docker push $PACKAGE_REGISTRY/php:latest$PR_TAG
 
-  build-phpunit-images:
-    name: PHPUnit on PHP ${{ matrix.php }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        php: [ %%PHP_VERSION_LIST%% ]
-
-    env:
-      PHP_VERSION: ${{ matrix.php }}
-      PHP_LATEST: '%%PHP_LATEST%%'
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG images/$PHP_VERSION/phpunit
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG
-
-      - name: Tag and push image as latest
-        if: ${{ env.PHP_LATEST == env.PHP_VERSION }}
-        run: |
-          docker image tag $PACKAGE_REGISTRY/phpunit:$PHP_VERSION-fpm$PR_TAG $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-          docker push $PACKAGE_REGISTRY/phpunit:latest$PR_TAG
-
-  build-specific-phpunit-images:
-    name: PHPUnit ${{ matrix.phpunit }}
-    runs-on: ubuntu-latest
-    needs: build-php-images
-    strategy:
-      matrix:
-        phpunit: [ %%PHPUNIT_COMBINATIONS%% ]
-
-    env:
-      PHPUNIT_VERSION: ${{ matrix.phpunit }}
-
-    steps:
-      - name: Checkout repository
-        uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
-
-      - name: Login to the package registry
-        run: |
-          echo "$REGISTRY_PASSWORD" | docker login $PACKAGE_REGISTRY_HOST -u "$REGISTRY_USERNAME" --password-stdin
-
-      - name: Build Docker image
-        run: docker build --build-arg PACKAGE_REGISTRY=$PACKAGE_REGISTRY --build-arg PR_TAG=$PR_TAG -t $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG images/phpunit/$PHPUNIT_VERSION
-
-      - name: Log Docker images
-        run: docker images
-
-      - name: Push Docker image
-        run: docker push $PACKAGE_REGISTRY/phpunit:$PHPUNIT_VERSION-fpm$PR_TAG
-
   build-cli-images:
     name: CLI on PHP ${{ matrix.php }}
     runs-on: ubuntu-latest
diff --git a/update.php b/update.php
index c3515f6..d6c2a97 100644
--- a/update.php
+++ b/update.php
@@ -282,9 +282,12 @@
  * Different WordPress versions support different versions of PHP and different versions of PHPUnit.
  * This creates a need to run multiple versions of PHPUnit on each version of PHP.
  *
- * @param array $phpunit_version A list of PHP versions for each PHPUnit version.
+ * These versions of PHPUnit are no longer supported and do not receive updates.
+ * Regenerating these containers should very rarely be required.
+ *
+ * @param array $legacy_phpunit_versions A list of PHP versions for each PHPUnit version.
  */
-$phpunit_versions = array(
+$legacy_phpunit_versions = array(
 	'9' => array(
 		'8.3',
 		'8.2',
@@ -342,8 +345,6 @@
 	'cli'     => file_get_contents( 'templates/Dockerfile-cli.template' ),
 );
 
-$phpunit_combinations = array();
-
 // Loop through each PHP version, and generate the Dockerfiles.
 foreach ( array_merge( $legacy_php_versions, $php_versions ) as $version => $images ) {
 	$title = "| PHP $version |";
@@ -500,50 +501,6 @@
 		echo "✅\n";
 	}
 
-	foreach ( $phpunit_versions as $phpunit_version => $supported_php_versions ) {
-		if ( in_array( $version, $supported_php_versions, true ) ) {
-			echo str_pad( "phpunit $phpunit_version", 15, '.' );
-
-			$php_version = $version;
-
-			if ( ! isset( $legacy_php_versions[ $php_version ] ) ) {
-				$phpunit_combinations[] = "{$phpunit_version}-php-{$php_version}";
-			}
-			echo shell_exec( "mkdir -p images/phpunit/{$phpunit_version}-php-{$php_version}" );
-
-			$dockerfile = $templates['phpunit'];
-
-			// Ensure PHPUnit can be successfully downloaded in older containers.
-			if ( '7.1' > $version ) {
-				$dockerfile = str_replace( 'RUN curl -sL', 'RUN curl -sLk', $dockerfile );
-			}
-
-			$dockerfile = str_replace( '%%GENERATED_WARNING%%', $generated_warning, $dockerfile );
-
-			if ( 'latest' === $php_version ) {
-				$version_tag = 'latest';
-			} else {
-				$version_tag = "$php_version-fpm";
-			}
-			$dockerfile = str_replace( '%%VERSION_TAG%%', $version_tag, $dockerfile );
-
-			$dockerfile = str_replace( '%%PHPUNIT_VERSION%%', $phpunit_version, $dockerfile );
-
-			// Cleanup any leftover tags.
-			$dockerfile = preg_replace( '/%%[^%]+%%/', '', $dockerfile );
-
-			// Write the real Dockerfile.
-			write_file( "images/phpunit/{$phpunit_version}-php-{$php_version}/Dockerfile", $dockerfile );
-
-			// Copy the entrypoint script, if it exists.
-			if ( file_exists( "entrypoint/entrypoint-phpunit.sh" ) ) {
-				copy( "entrypoint/entrypoint-phpunit.sh", "images/phpunit/{$phpunit_version}-php-{$php_version}/entrypoint.sh" );
-			}
-
-			echo "✅\n";
-		}
-	}
-
 	$workflow_templates = array(
 		'docker-hub.yml' => 'GITHUB',
 		'github-container-registry.yml' => 'DOCKER_HUB',
@@ -556,9 +513,6 @@
 	$php_version_list = "'" . implode( "', '", array_keys( $php_versions ) ) . "'";
 	$workflow_template = str_replace( '%%PHP_VERSION_LIST%%', $php_version_list, $workflow_template );
 
-	$phpunit_version_list = "'" . implode( "', '", array_values( $phpunit_combinations ) ) . "'";
-	$workflow_template = str_replace( '%%PHPUNIT_COMBINATIONS%%', $phpunit_version_list, $workflow_template );
-
 	$workflow_template = str_replace( '%%PHP_LATEST%%', $latest, $workflow_template );
 
 	foreach ( $workflow_templates as $name => $remove_pattern ) {