diff --git a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
index f2470d542f3e5..08b72a4484815 100644
--- a/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
+++ b/src/Symfony/Bundle/FrameworkBundle/CHANGELOG.md
@@ -8,6 +8,7 @@ CHANGELOG
  * Derivate `kernel.secret` from the decryption secret when its env var is not defined
  * Make the `config/` directory optional in `MicroKernelTrait`, add support for service arguments in the
    invokable Kernel class, and register `FrameworkBundle` by default when the `bundles.php` file is missing
+ * Split "var/build" from "var/cache" when compiling for the "prod" env
 
 7.1
 ---
diff --git a/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php b/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
index f40373a302b45..f499c66127060 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Kernel/MicroKernelTrait.php
@@ -18,6 +18,7 @@
 use Symfony\Component\DependencyInjection\Loader\Configurator\ContainerConfigurator;
 use Symfony\Component\DependencyInjection\Loader\PhpFileLoader as ContainerPhpFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
+use Symfony\Component\HttpKernel\Kernel;
 use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator;
 use Symfony\Component\Routing\Loader\PhpFileLoader as RoutingPhpFileLoader;
 use Symfony\Component\Routing\RouteCollection;
@@ -120,6 +121,9 @@ public function getBuildDir(): string
         if (isset($_SERVER['APP_BUILD_DIR'])) {
             return $_SERVER['APP_BUILD_DIR'].'/'.$this->environment;
         }
+        if ('prod' === $this->getEnvironment() && Kernel::class === (new \ReflectionMethod(parent::class, 'getCacheDir'))->class) {
+            return $this->getProjectDir().'/var/build/'.$this->environment;
+        }
 
         return parent::getBuildDir();
     }