diff --git a/src/BrefKernel.php b/src/BrefKernel.php
index f51789c..6e5b481 100644
--- a/src/BrefKernel.php
+++ b/src/BrefKernel.php
@@ -10,6 +10,13 @@
 
 abstract class BrefKernel extends Kernel
 {
+    public function __construct(string $environment, bool $debug)
+    {
+        parent::__construct($environment, $debug);
+
+        $this->configureCacheDir();
+    }
+
     public function isLambda(): bool
     {
         return getenv('LAMBDA_TASK_ROOT') !== false;
@@ -135,6 +142,15 @@ private function ensureLogDir(string $writeLogDir): void
         $filesystem->mkdir($writeLogDir);
     }
 
+    private function configureCacheDir(): void
+    {
+        if (isset($_SERVER['APP_CACHE_DIR']) || ! $this->isLambda()) {
+            return;
+        }
+
+        $_SERVER['APP_CACHE_DIR'] = '/tmp/cache';
+    }
+
     /**
      * This method logs to stderr.
      *
diff --git a/tests/Unit/BrefKernelTest.php b/tests/Unit/BrefKernelTest.php
index 8cf31e1..95791cc 100644
--- a/tests/Unit/BrefKernelTest.php
+++ b/tests/Unit/BrefKernelTest.php
@@ -7,6 +7,42 @@
 
 class BrefKernelTest extends TestCase
 {
+    /** @var string|false */
+    private $lambdaTaskRoot;
+
+    /** @var string|false */
+    private $appCacheDir;
+
+    /** @var string|null */
+    private $serverAppCacheDir;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->lambdaTaskRoot = getenv('LAMBDA_TASK_ROOT');
+        $this->appCacheDir = getenv('APP_CACHE_DIR');
+        $this->serverAppCacheDir = $_SERVER['APP_CACHE_DIR'] ?? null;
+
+        putenv('LAMBDA_TASK_ROOT');
+        putenv('APP_CACHE_DIR');
+        unset($_SERVER['APP_CACHE_DIR']);
+    }
+
+    protected function tearDown(): void
+    {
+        $this->restoreEnvironmentVariable('LAMBDA_TASK_ROOT', $this->lambdaTaskRoot);
+        $this->restoreEnvironmentVariable('APP_CACHE_DIR', $this->appCacheDir);
+
+        if ($this->serverAppCacheDir === null) {
+            unset($_SERVER['APP_CACHE_DIR']);
+        } else {
+            $_SERVER['APP_CACHE_DIR'] = $this->serverAppCacheDir;
+        }
+
+        parent::tearDown();
+    }
+
     public function testIsLambda()
     {
         $kernel = new TestKernel;
@@ -15,4 +51,52 @@ public function testIsLambda()
         putenv('LAMBDA_TASK_ROOT=/var/task');
         self::assertTrue($kernel->isLambda());
     }
+
+    public function testItConfiguresSymfonyCacheDirOnLambda(): void
+    {
+        putenv('LAMBDA_TASK_ROOT=/var/task');
+
+        new TestKernel;
+
+        self::assertSame('/tmp/cache', $_SERVER['APP_CACHE_DIR']);
+    }
+
+    public function testItDoesNotConfigureSymfonyCacheDirOutsideLambda(): void
+    {
+        new TestKernel;
+
+        self::assertArrayNotHasKey('APP_CACHE_DIR', $_SERVER);
+    }
+
+    public function testItDoesNotOverrideSymfonyCacheDir(): void
+    {
+        putenv('LAMBDA_TASK_ROOT=/var/task');
+        $_SERVER['APP_CACHE_DIR'] = '/custom/cache';
+
+        new TestKernel;
+
+        self::assertSame('/custom/cache', $_SERVER['APP_CACHE_DIR']);
+    }
+
+    public function testItUsesConfiguredSymfonyCacheDirEnvironmentVariable(): void
+    {
+        putenv('LAMBDA_TASK_ROOT=/var/task');
+        $_SERVER['APP_CACHE_DIR'] = '/custom/cache';
+
+        new TestKernel;
+
+        self::assertSame('/custom/cache', $_SERVER['APP_CACHE_DIR']);
+    }
+
+    /**
+     * @param string|false $value
+     */
+    private function restoreEnvironmentVariable(string $name, $value): void
+    {
+        if ($value === false) {
+            putenv($name);
+        } else {
+            putenv($name . '=' . $value);
+        }
+    }
 }