diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index 596535597ae..bb2ed371407 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -2436,6 +2436,16 @@ jobs:
                 exit 1
               fi
 
+          # another program that loads PHPStan restarts through
+          # TurboProcessRestarter, and can leave OPcache dormant: the same
+          # single restart disarms pcov, and no process turns OPcache on
+          - operating-system: "ubuntu-latest"
+            coverage: "pcov"
+            extensions: ""
+            script: |
+              php restart-without-opcache.php analyse --no-progress
+              php check.php restarted-for=pcov pcov-armed=no opcache-cli-on=no processes=2+ starts=2
+
           # --debug restarts like any other run - it only makes the analysis
           # serial, --xdebug is what keeps xdebug
           - operating-system: "ubuntu-latest"
diff --git a/e2e/restart-manager/restart-without-opcache.php b/e2e/restart-manager/restart-without-opcache.php
new file mode 100644
index 00000000000..6e1368fa625
--- /dev/null
+++ b/e2e/restart-manager/restart-without-opcache.php
@@ -0,0 +1,22 @@
+<?php declare(strict_types = 1);
+
+use PHPStan\Turbo\TurboProcessRestarter;
+
+// Restarts the way another program that loads PHPStan does, Rector for
+// example, but without OPcache. bin/phpstan then sees the marker and does not
+// restart a second time. The restart classes are loaded by file like in
+// bin/phpstan, which needs to be the first to require vendor/autoload.php.
+$src = __DIR__ . '/../../src';
+require_once $src . '/Turbo/TurboExtensionEnabler.php';
+require_once $src . '/Turbo/TurboExtensionSelector.php';
+require_once $src . '/Process/Restart/RestartReason.php';
+require_once $src . '/Process/Restart/OpcacheSettings.php';
+require_once $src . '/Process/Restart/RestartExtensionRegistry.php';
+require_once $src . '/Process/Restart/IniComposer.php';
+require_once $src . '/Process/Restart/RestartExecutor.php';
+require_once $src . '/Process/Restart/RestartManager.php';
+require_once $src . '/Turbo/TurboProcessRestarter.php';
+
+TurboProcessRestarter::restartIfSuitable($_SERVER['argv'], null, 'phpstan', false);
+
+require __DIR__ . '/../../bin/phpstan';
diff --git a/src/Turbo/TurboProcessRestarter.php b/src/Turbo/TurboProcessRestarter.php
index a671244afa4..882970003fb 100644
--- a/src/Turbo/TurboProcessRestarter.php
+++ b/src/Turbo/TurboProcessRestarter.php
@@ -24,11 +24,32 @@ final class TurboProcessRestarter
 	 * in $argv or <APP>_ALLOW_XDEBUG is set - the variable composer/xdebug-handler
 	 * reads for that application, so a caller can drop its own xdebug restart.
 	 *
+	 * With $withOpcache false, the restart does not turn on OPcache. A run
+	 * that mostly reads the result cache is then faster, and a full analysis
+	 * uses a little more CPU.
+	 *
 	 * @api
 	 * @param list<string> $argv
 	 */
-	public static function restartIfSuitable(array $argv, ?string $pharPath = null, ?string $appName = null): void
+	public static function restartIfSuitable(array $argv, ?string $pharPath = null, ?string $appName = null, bool $withOpcache = true): void
 	{
+		if (!$withOpcache) {
+			$extensions = $appName === null
+				? [
+					'phpstan_turbo',
+					'tideways',
+				]
+				: [
+					'xdebug',
+					'pcov',
+					'uopz',
+					'phpstan_turbo',
+					'tideways',
+				];
+			RestartManager::run($argv, $pharPath, $extensions, $appName ?? 'phpstan');
+			return;
+		}
+
 		if ($appName === null) {
 			RestartManager::run($argv, $pharPath, ['phpstan_turbo', 'tideways', 'opcache']);
 			return;