diff --git a/.github/workflows/e2e-tests.yml b/.github/workflows/e2e-tests.yml
index f0d1a19ad6e..aa99478278d 100644
--- a/.github/workflows/e2e-tests.yml
+++ b/.github/workflows/e2e-tests.yml
@@ -2576,6 +2576,17 @@ jobs:
               fi
               php check.php restarted-for=xdebug,opcache xdebug-armed=no xdebug-loaded=yes processes=2+ starts=2
 
+          # xdebug armed in php.ini, disarmed with `php -d xdebug.mode=off`:
+          # nothing to restart for, and the spawned workers do not inherit the
+          # -d flag - ProcessHelper has to pass the switch on, or they run with
+          # the php.ini's xdebug.mode
+          - operating-system: "windows-latest"
+            coverage: "xdebug"
+            extensions: ""
+            script: |
+              php -d xdebug.mode=off ../../bin/phpstan analyse --no-progress
+              php check.php restarted-for= xdebug-armed=no xdebug-loaded=yes processes=2+ starts=1
+
           # XDEBUG_MODE overrides xdebug.mode, so flagging the ini alone would
           # be silently overridable - the row exports the env var too
           - operating-system: "ubuntu-latest"
diff --git a/src/Parallel/ForkParallelChecker.php b/src/Parallel/ForkParallelChecker.php
index 38da59a37ba..0645576069d 100644
--- a/src/Parallel/ForkParallelChecker.php
+++ b/src/Parallel/ForkParallelChecker.php
@@ -8,6 +8,7 @@
 use PHPStan\Diagnose\DiagnoseExtension;
 use PHPStan\Process\ProcessHelper;
 use PHPStan\Process\Restart\OpcacheSettings;
+use PHPStan\Process\Restart\RestartExtensionRegistry;
 use PHPStan\Turbo\TurboExtensionEnabler;
 use function function_exists;
 use function getmypid;
@@ -72,7 +73,7 @@ public function print(Output $output): void
 		// (see ProcessHelper); the extension path is on the turbo lines
 		$parentPid = getmypid();
 		$output->writeLineFormatted('Worker -d entries:');
-		foreach (ProcessHelper::resolveWorkerIniEntries(OpcacheSettings::getIniEntries(), PHP_OS_FAMILY, $parentPid === false ? 0 : $parentPid, 1) as $iniEntry) {
+		foreach (ProcessHelper::resolveWorkerIniEntries(OpcacheSettings::getIniEntries(), RestartExtensionRegistry::getStartupSwitches(), PHP_OS_FAMILY, $parentPid === false ? 0 : $parentPid, 1) as $iniEntry) {
 			$output->writeLineFormatted(sprintf(
 				'  %s%s',
 				$iniEntry,
diff --git a/src/Process/ProcessHelper.php b/src/Process/ProcessHelper.php
index a24975c10f5..460e119b41a 100644
--- a/src/Process/ProcessHelper.php
+++ b/src/Process/ProcessHelper.php
@@ -4,6 +4,7 @@
 
 use PHPStan\Command\AnalyseCommand;
 use PHPStan\Process\Restart\OpcacheSettings;
+use PHPStan\Process\Restart\RestartExtensionRegistry;
 use PHPStan\Process\Restart\RestartManager;
 use PHPStan\Turbo\TurboExtensionSelector;
 use Symfony\Component\Console\Input\InputInterface;
@@ -76,9 +77,10 @@ public static function getWorkerCommand(
 
 		$parentPid = getmypid();
 		self::$spawnedWorkerCount++;
-		foreach (self::resolveWorkerIniEntries(OpcacheSettings::getIniEntries(), PHP_OS_FAMILY, $parentPid === false ? 0 : $parentPid, self::$spawnedWorkerCount) as $iniEntry) {
+		foreach (self::resolveWorkerIniEntries(OpcacheSettings::getIniEntries(), RestartExtensionRegistry::getStartupSwitches(), PHP_OS_FAMILY, $parentPid === false ? 0 : $parentPid, self::$spawnedWorkerCount) as $iniEntry) {
 			$processCommandArray[] = '-d';
-			$processCommandArray[] = $iniEntry;
+			// xdebug.mode can be a list with spaces in it
+			$processCommandArray[] = escapeshellarg($iniEntry);
 		}
 
 		foreach ([$mainScript, $commandName] as $arg) {
@@ -154,18 +156,28 @@ public static function getWorkerCommand(
 	 * model spawned workers have elsewhere, where the segment is an anonymous
 	 * mapping private to the process.
 	 *
+	 * The startup switches of xdebug, pcov and uopz are repeated as the
+	 * spawning process has them. Where it got them through `-d` - `php -d
+	 * xdebug.mode=off` with xdebug armed in the php.ini - it had nothing to
+	 * restart for, and the worker would otherwise run with the php.ini's
+	 * armed extension.
+	 *
 	 * The restart marker closes the loop: the worker's configuration is
 	 * decided here, so the worker must not restart itself.
 	 *
 	 * @param list<string> $opcacheArgs OpcacheSettings::getIniEntries() of the spawning process
+	 * @param array<string, string> $startupSwitches RestartExtensionRegistry::getStartupSwitches() of the spawning process
 	 * @return list<string>
 	 */
-	public static function resolveWorkerIniEntries(array $opcacheArgs, string $osFamily, int $parentPid, int $workerNumber): array
+	public static function resolveWorkerIniEntries(array $opcacheArgs, array $startupSwitches, string $osFamily, int $parentPid, int $workerNumber): array
 	{
 		$entries = $opcacheArgs;
 		if ($entries !== [] && $osFamily === 'Windows') {
 			$entries[] = sprintf('opcache.cache_id=phpstan-%d-%d', $parentPid, $workerNumber);
 		}
+		foreach ($startupSwitches as $name => $value) {
+			$entries[] = sprintf('%s=%s', $name, $value);
+		}
 		$entries[] = RestartManager::RESTARTED_INI . '=1';
 
 		return $entries;
diff --git a/src/Process/Restart/RestartExtensionRegistry.php b/src/Process/Restart/RestartExtensionRegistry.php
index 55fc5e783d8..cf69c49df33 100644
--- a/src/Process/Restart/RestartExtensionRegistry.php
+++ b/src/Process/Restart/RestartExtensionRegistry.php
@@ -90,15 +90,7 @@ final class RestartExtensionRegistry
 	 */
 	public static function collectReasons(bool $allowXdebug, ?string $pharPath = null): array
 	{
-		$iniSettings = [];
-		foreach (['xdebug.mode', 'pcov.enabled', 'uopz.disable'] as $name) {
-			$value = ini_get($name);
-			if ($value === false) {
-				continue;
-			}
-
-			$iniSettings[$name] = $value;
-		}
+		$iniSettings = self::getStartupSwitches();
 
 		// XDEBUG_MODE wins over the ini file, so the effective mode - not the
 		// configured one - is what decides. Resolved here rather than in
@@ -120,6 +112,30 @@ public static function collectReasons(bool $allowXdebug, ?string $pharPath = nul
 		);
 	}
 
+	/**
+	 * The startup switches of the flag rows (xdebug.mode, pcov.enabled,
+	 * uopz.disable) as the current process has them, for each extension that
+	 * is loaded. A switch set with `-d` - `php -d xdebug.mode=off` - leaves
+	 * nothing to restart for, and is not inherited by spawned workers either,
+	 * so ProcessHelper passes these on.
+	 *
+	 * @return array<string, string>
+	 */
+	public static function getStartupSwitches(): array
+	{
+		$iniSettings = [];
+		foreach (['xdebug.mode', 'pcov.enabled', 'uopz.disable'] as $name) {
+			$value = ini_get($name);
+			if ($value === false) {
+				continue;
+			}
+
+			$iniSettings[$name] = $value;
+		}
+
+		return $iniSettings;
+	}
+
 	/**
 	 * @param list<string> $loadedExtensions
 	 * @param array<string, string> $iniSettings
diff --git a/src/Process/Restart/RestartManager.php b/src/Process/Restart/RestartManager.php
index e701548eb7f..1cf45099576 100644
--- a/src/Process/Restart/RestartManager.php
+++ b/src/Process/Restart/RestartManager.php
@@ -458,6 +458,13 @@ private static function getPassedThroughArguments(): array
 		$arguments[] = '-d';
 		$arguments[] = 'memory_limit=' . ini_get('memory_limit');
 
+		// `php -d xdebug.mode=off` left nothing to restart for, and the
+		// restarted process must not get the php.ini's armed xdebug back
+		foreach (RestartExtensionRegistry::getStartupSwitches() as $name => $value) {
+			$arguments[] = '-d';
+			$arguments[] = $name . '=' . $value;
+		}
+
 		return $arguments;
 	}
 
diff --git a/tests/PHPStan/Process/ProcessHelperTest.php b/tests/PHPStan/Process/ProcessHelperTest.php
index 13cd94bd7e4..c063374efa1 100644
--- a/tests/PHPStan/Process/ProcessHelperTest.php
+++ b/tests/PHPStan/Process/ProcessHelperTest.php
@@ -3,6 +3,7 @@
 namespace PHPStan\Process;
 
 use PHPStan\Process\Restart\OpcacheSettings;
+use PHPStan\Process\Restart\RestartExtensionRegistry;
 use PHPStan\Process\Restart\RestartManager;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
@@ -19,26 +20,33 @@ final class ProcessHelperTest extends TestCase
 {
 
 	/**
-	 * @return iterable<string, array{list<string>, string, list<string>}>
+	 * @return iterable<string, array{list<string>, array<string, string>, string, list<string>}>
 	 */
 	public static function dataResolveWorkerIniEntries(): iterable
 	{
 		$opcacheArgs = ['opcache.enable=1', 'opcache.enable_cli=1'];
-		yield 'linux' => [$opcacheArgs, 'Linux', ['opcache.enable=1', 'opcache.enable_cli=1', 'phpstan.restarted=1']];
-		yield 'darwin' => [$opcacheArgs, 'Darwin', ['opcache.enable=1', 'opcache.enable_cli=1', 'phpstan.restarted=1']];
-		yield 'windows' => [$opcacheArgs, 'Windows', ['opcache.enable=1', 'opcache.enable_cli=1', 'opcache.cache_id=phpstan-4242-7', 'phpstan.restarted=1']];
-		yield 'linux without OPcache' => [[], 'Linux', ['phpstan.restarted=1']];
-		yield 'windows without OPcache' => [[], 'Windows', ['phpstan.restarted=1']];
+		yield 'linux' => [$opcacheArgs, [], 'Linux', ['opcache.enable=1', 'opcache.enable_cli=1', 'phpstan.restarted=1']];
+		yield 'darwin' => [$opcacheArgs, [], 'Darwin', ['opcache.enable=1', 'opcache.enable_cli=1', 'phpstan.restarted=1']];
+		yield 'windows' => [$opcacheArgs, [], 'Windows', ['opcache.enable=1', 'opcache.enable_cli=1', 'opcache.cache_id=phpstan-4242-7', 'phpstan.restarted=1']];
+		yield 'linux without OPcache' => [[], [], 'Linux', ['phpstan.restarted=1']];
+		yield 'windows without OPcache' => [[], [], 'Windows', ['phpstan.restarted=1']];
+		yield 'windows with xdebug and pcov switched off by -d' => [
+			$opcacheArgs,
+			['xdebug.mode' => 'off', 'pcov.enabled' => '0'],
+			'Windows',
+			['opcache.enable=1', 'opcache.enable_cli=1', 'opcache.cache_id=phpstan-4242-7', 'xdebug.mode=off', 'pcov.enabled=0', 'phpstan.restarted=1'],
+		];
 	}
 
 	/**
 	 * @param list<string> $opcacheArgs
+	 * @param array<string, string> $startupSwitches
 	 * @param list<string> $expected
 	 */
 	#[DataProvider('dataResolveWorkerIniEntries')]
-	public function testResolveWorkerIniEntries(array $opcacheArgs, string $osFamily, array $expected): void
+	public function testResolveWorkerIniEntries(array $opcacheArgs, array $startupSwitches, string $osFamily, array $expected): void
 	{
-		$this->assertSame($expected, ProcessHelper::resolveWorkerIniEntries($opcacheArgs, $osFamily, 4242, 7));
+		$this->assertSame($expected, ProcessHelper::resolveWorkerIniEntries($opcacheArgs, $startupSwitches, $osFamily, 4242, 7));
 	}
 
 	public function testWorkerCommandCarriesTheIniEntries(): void
@@ -48,12 +56,16 @@ public function testWorkerCommandCarriesTheIniEntries(): void
 
 		$opcacheArgs = OpcacheSettings::getIniEntries();
 		foreach ($opcacheArgs as $opcacheArg) {
-			$this->assertStringContainsString(sprintf(' -d %s ', $opcacheArg), $command);
+			$this->assertStringContainsString(sprintf(' -d %s ', escapeshellarg($opcacheArg)), $command);
+		}
+
+		foreach (RestartExtensionRegistry::getStartupSwitches() as $name => $value) {
+			$this->assertStringContainsString(sprintf(' -d %s ', escapeshellarg($name . '=' . $value)), $command);
 		}
 
 		// the restart marker is the last -d, right before the script
 		$this->assertStringContainsString(
-			sprintf(' -d %s=1 %s %s ', RestartManager::RESTARTED_INI, escapeshellarg('bin/phpstan'), escapeshellarg('worker')),
+			sprintf(' -d %s %s %s ', escapeshellarg(RestartManager::RESTARTED_INI . '=1'), escapeshellarg('bin/phpstan'), escapeshellarg('worker')),
 			$command,
 		);
 
@@ -63,8 +75,8 @@ public function testWorkerCommandCarriesTheIniEntries(): void
 		}
 
 		// every Windows worker gets its own OPcache instance
-		$this->assertSame(1, preg_match('~ -d opcache\.cache_id=(phpstan-\d+-\d+) ~', $command, $matches));
-		$this->assertSame(1, preg_match('~ -d opcache\.cache_id=(phpstan-\d+-\d+) ~', $commandAgain, $matchesAgain));
+		$this->assertSame(1, preg_match('~ -d [\'"]?opcache\.cache_id=(phpstan-\d+-\d+)[\'"]? ~', $command, $matches));
+		$this->assertSame(1, preg_match('~ -d [\'"]?opcache\.cache_id=(phpstan-\d+-\d+)[\'"]? ~', $commandAgain, $matchesAgain));
 		$this->assertNotSame($matches[1], $matchesAgain[1]);
 	}