diff --git a/CHANGELOG.md b/CHANGELOG.md
index ad51581e7..26e90d13a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [unreleased] Unreleased
 
+## Fixed
+
+- Fallback for missing `$_composer_autoload_path` file. (thanks @andronocean)
+
+
 ## [3.7.6] 2024-10-18;
 
 ### Changed
diff --git a/src/Utils/Composer.php b/src/Utils/Composer.php
index 337d7bbad..1d9ce5ac8 100644
--- a/src/Utils/Composer.php
+++ b/src/Utils/Composer.php
@@ -4,6 +4,7 @@
 
 namespace lucatume\WPBrowser\Utils;
 
+use Codeception\Codecept;
 use JsonException;
 use lucatume\WPBrowser\Adapters\Symfony\Component\Process\Process;
 use lucatume\WPBrowser\Exceptions\RuntimeException;
@@ -33,8 +34,21 @@ public static function vendorDir(?string $path = null): string
 
     public static function autoloadPath(): string
     {
+        /**
+         * If `$_composer_autoload_path` is undefined, fall back to `vendor/autoload.php`
+         * in the parent project's directory.
+         *
+         * @link https://getcomposer.org/doc/articles/vendor-binaries.md#finding-the-composer-autoloader-from-a-binary
+         */
         global $_composer_autoload_path;
-        return realpath($_composer_autoload_path) ?: $_composer_autoload_path;
+        if (isset($_composer_autoload_path)) {
+            $autoloadPath = $_composer_autoload_path;
+        } else {
+            // We use the Codecept class to find the location of Composer's vendor-dir.
+            $vendorDir = dirname((string)(new \ReflectionClass(Codecept::class))->getFilename(), 5);
+            $autoloadPath = $vendorDir . DIRECTORY_SEPARATOR . 'autoload.php';
+        }
+        return realpath($autoloadPath) ?: $autoloadPath;
     }
 
     public static function binDir(?string $path = null): string
diff --git a/tests/unit/lucatume/WPBrowser/Utils/ComposerTest.php b/tests/unit/lucatume/WPBrowser/Utils/ComposerTest.php
index caae55f04..25e371599 100644
--- a/tests/unit/lucatume/WPBrowser/Utils/ComposerTest.php
+++ b/tests/unit/lucatume/WPBrowser/Utils/ComposerTest.php
@@ -228,4 +228,36 @@ public function should_build_on_the_project_composer_file_if_no_composer_file_sp
             $composer->getDecodedContents()
         );
     }
+
+    /**
+     * The `autoloadPath` static method should return `$_composer_autoload_path` if it is defined
+     *
+     * @test
+     * @backupGlobals enabled
+     */
+    public function static_autoload_path_should_return_global_composer_autoload_path(): void
+    {
+        // Ensure that it's set for this test.
+        global $_composer_autoload_path;
+        $_composer_autoload_path = codecept_root_dir() . 'vendor/autoload.php';
+
+        $this->assertSame($_composer_autoload_path, Composer::autoloadPath() );
+    }
+
+    /**
+     * The `autoloadPath` static method should find the autoload.php file itself if the global `$_composer_autoload_path` is undefined
+     *
+     * @test
+     * @backupGlobals enabled
+     */
+    public function static_autoload_path_should_use_fallback(): void
+    {
+        // clear value to enable fallback
+        unset($GLOBALS['_composer_autoload_path']);
+
+        $autoloadPath = Composer::autoloadPath();
+
+        $this->assertSame(codecept_root_dir() . 'vendor/autoload.php', $autoloadPath );
+        $this->assertFileExists( $autoloadPath );
+    }
 }