diff --git a/src/Command/ExecuteSuite.php b/src/Command/ExecuteSuite.php
index b9afe06..72d9dcc 100644
--- a/src/Command/ExecuteSuite.php
+++ b/src/Command/ExecuteSuite.php
@@ -117,6 +117,7 @@ protected function outputTitle()
 
     public function execute(InputInterface $input, OutputInterface $output): int
     {
+        $this->beginRun();
         $this->handleDir(dirname($this->file));
         $this->cli = true;
         $this->output = $output;
@@ -295,14 +296,36 @@ public function execute(InputInterface $input, OutputInterface $output): int
             $this->success('Rapport visuel écrit dans ' . $visualPath, newLine: true, force: true);
         }
 
+        $this->releaseBrowser();
+
+        return $summary->hasFailures() ? Command::FAILURE : Command::SUCCESS;
+    }
+
+    /**
+     * Give this run a browser of its own.
+     *
+     * The run ends by closing its browser (releaseBrowser()), so it must never
+     * pick up one another PrestaFlow process is driving, nor let that process
+     * find and close its own. Scoping the socket file to this run does both.
+     */
+    public function beginRun(): void
+    {
+        \PrestaFlow\Library\Tests\TestsSuite::scopeBrowserFilesTo(
+            'run-' . getmypid() . '-' . bin2hex(random_bytes(4))
+        );
+    }
+
+    /**
+     * Close the browser this run launched and forget its socket file.
+     */
+    public function releaseBrowser(): void
+    {
         try {
             \PrestaFlow\Library\Tests\TestsSuite::getBrowser(force: false)?->close();
         } catch (\Throwable $e) {
         }
         @unlink(\PrestaFlow\Library\Tests\TestsSuite::getFilePath('.browser'));
         @unlink(\PrestaFlow\Library\Tests\TestsSuite::getFilePath('.browser-options'));
-
-        return $summary->hasFailures() ? Command::FAILURE : Command::SUCCESS;
     }
 
     protected function handleDir($path)
diff --git a/src/Tests/TestsSuite.php b/src/Tests/TestsSuite.php
index 4e5af19..805272d 100644
--- a/src/Tests/TestsSuite.php
+++ b/src/Tests/TestsSuite.php
@@ -154,6 +154,11 @@ private static function buildVisualBlock(int $startIndex): array
     protected static $browserInstance = null;
     protected static ?string $browserInstanceSocket = null;
 
+    /**
+     * Owner of the keepAlive browser files, see scopeBrowserFilesTo().
+     */
+    protected static ?string $browserFilesScope = null;
+
     protected $draft = false;
     protected $groups = 'all';
 
@@ -316,8 +321,30 @@ public function getGroups() : string|array
         return $this->groups;
     }
 
+    /**
+     * Scope the keepAlive browser files (socket, options) to one run.
+     *
+     * Without a scope they sit at one path per machine, which every PrestaFlow
+     * process shares: a run would reconnect to the Chrome another run is
+     * driving, and ExecuteSuite, which closes that browser and deletes the file
+     * when it ends, would tear it down under the other run ("The page was
+     * closed and is not available anymore"). A run scopes the files to itself
+     * so it only ever finds, and releases, the browser it launched.
+     *
+     * Null restores the shared path, for callers outside ExecuteSuite that
+     * rely on reconnecting to an existing browser.
+     */
+    public static function scopeBrowserFilesTo(?string $scope): void
+    {
+        self::$browserFilesScope = ($scope === null || $scope === '') ? null : $scope;
+    }
+
     public static function getFilePath($filename = '.browser')
     {
+        if (self::$browserFilesScope !== null) {
+            $filename = self::$browserFilesScope.'-'.$filename;
+        }
+
         if (function_exists('storage_path')) {
             $dir = storage_path().'/datas';
             if (!is_dir($dir)) {
diff --git a/tests/Unit/Command/BrowserOwnershipTest.php b/tests/Unit/Command/BrowserOwnershipTest.php
new file mode 100644
index 0000000..eb7aa3f
--- /dev/null
+++ b/tests/Unit/Command/BrowserOwnershipTest.php
@@ -0,0 +1,90 @@
+<?php
+
+namespace PrestaFlow\Tests\Unit\Command;
+
+use PHPUnit\Framework\TestCase;
+use PrestaFlow\Library\Command\ExecuteSuite;
+use PrestaFlow\Library\Tests\TestsSuite;
+
+/**
+ * Two runs on the same machine must not share, nor tear down, each other's
+ * browser.
+ *
+ * The keepAlive browser is found again through a socket file. That file used
+ * to sit at one fixed path per machine, so every run read and wrote the same
+ * one, and every run ended by closing the browser the file named and deleting
+ * it. A run that finished — even a browser-free one — closed the Chrome another
+ * run was driving, which then failed with "The page was closed and is not
+ * available anymore".
+ *
+ * No browser is needed: the socket file points to a port nothing listens on,
+ * so releaseBrowser() cannot connect and only its file handling is exercised.
+ */
+final class BrowserOwnershipTest extends TestCase
+{
+    private array $files = [];
+
+    protected function tearDown(): void
+    {
+        foreach ($this->files as $file) {
+            @unlink($file);
+        }
+        TestsSuite::scopeBrowserFilesTo(null);
+    }
+
+    public function testARunThatEndsLeavesTheBrowserOfAnotherRunAlone(): void
+    {
+        $first = new ExecuteSuite();
+        $first->beginRun();
+        $firstSocketFile = TestsSuite::getFilePath('.browser');
+        $this->files[] = $firstSocketFile;
+        file_put_contents($firstSocketFile, 'ws://127.0.0.1:1/devtools/browser/first-run');
+
+        // A second run starts and finishes while the first is still driving
+        // its browser (in real life: another process, same temp dir).
+        $second = new ExecuteSuite();
+        $second->beginRun();
+        $this->files[] = TestsSuite::getFilePath('.browser');
+        $second->releaseBrowser();
+
+        $this->assertFileExists(
+            $firstSocketFile,
+            'the second run deleted the socket file of the first one'
+        );
+    }
+
+    public function testEachRunGetsItsOwnSocketFile(): void
+    {
+        $first = new ExecuteSuite();
+        $first->beginRun();
+        $firstSocketFile = TestsSuite::getFilePath('.browser');
+
+        $second = new ExecuteSuite();
+        $second->beginRun();
+
+        $this->assertNotSame($firstSocketFile, TestsSuite::getFilePath('.browser'));
+    }
+
+    public function testARunReleasesItsOwnSocketFile(): void
+    {
+        $run = new ExecuteSuite();
+        $run->beginRun();
+        $socketFile = TestsSuite::getFilePath('.browser');
+        $this->files[] = $socketFile;
+        file_put_contents($socketFile, 'ws://127.0.0.1:1/devtools/browser/own-run');
+
+        $run->releaseBrowser();
+
+        $this->assertFileDoesNotExist($socketFile);
+    }
+
+    public function testWithoutARunTheSharedPathIsUnchanged(): void
+    {
+        TestsSuite::scopeBrowserFilesTo(null);
+
+        $this->assertSame(
+            sys_get_temp_dir() . '/prestaflow-.browser',
+            TestsSuite::getFilePath('.browser')
+        );
+    }
+}