diff --git a/symfony/framework-bundle/3.3/post-install.txt b/symfony/framework-bundle/3.3/post-install.txt
index 6aaefd13..63d5e10c 100644
--- a/symfony/framework-bundle/3.3/post-install.txt
+++ b/symfony/framework-bundle/3.3/post-install.txt
@@ -5,7 +5,7 @@
   * <fg=blue>Run</> your application:
     1. Change to the project directory
     2. Create your code repository with the <comment>git init</comment> command
-    3. Execute the <comment>php -S 127.0.0.1:8000 -t public</> command
+    3. Execute the <comment>php -S 127.0.0.1:8000 -t public public/index.php</> command
     4. Browse to the <comment>http://localhost:8000/</> URL.
 
        Quit the server with CTRL-C.
diff --git a/symfony/framework-bundle/3.3/public/index.php b/symfony/framework-bundle/3.3/public/index.php
index 5283b7ce..7e5d9e9b 100644
--- a/symfony/framework-bundle/3.3/public/index.php
+++ b/symfony/framework-bundle/3.3/public/index.php
@@ -19,6 +19,10 @@ $env = $_SERVER['APP_ENV'] ?? $_ENV['APP_ENV'] ?? 'dev';
 $debug = (bool) ($_SERVER['APP_DEBUG'] ?? $_ENV['APP_DEBUG'] ?? ('prod' !== $env));
 
 if ($debug) {
+    // Compatibility with the built-in PHP web server
+    if ('/index.php' !== $_SERVER['SCRIPT_NAME'] && is_file(__DIR__.$_SERVER['SCRIPT_NAME'])) {
+        return false;
+    }
     umask(0000);
 
     Debug::enable();
diff --git a/symfony/framework-bundle/4.2/post-install.txt b/symfony/framework-bundle/4.2/post-install.txt
index 6aaefd13..63d5e10c 100644
--- a/symfony/framework-bundle/4.2/post-install.txt
+++ b/symfony/framework-bundle/4.2/post-install.txt
@@ -5,7 +5,7 @@
   * <fg=blue>Run</> your application:
     1. Change to the project directory
     2. Create your code repository with the <comment>git init</comment> command
-    3. Execute the <comment>php -S 127.0.0.1:8000 -t public</> command
+    3. Execute the <comment>php -S 127.0.0.1:8000 -t public public/index.php</> command
     4. Browse to the <comment>http://localhost:8000/</> URL.
 
        Quit the server with CTRL-C.
diff --git a/symfony/framework-bundle/4.2/public/index.php b/symfony/framework-bundle/4.2/public/index.php
index bdcf5f4d..6a6b9202 100644
--- a/symfony/framework-bundle/4.2/public/index.php
+++ b/symfony/framework-bundle/4.2/public/index.php
@@ -19,6 +19,10 @@ $env = $_SERVER['APP_ENV'] ?? $_ENV['APP_ENV'] ?? 'dev';
 $debug = (bool) ($_SERVER['APP_DEBUG'] ?? $_ENV['APP_DEBUG'] ?? ('prod' !== $env));
 
 if ($debug) {
+    // Compatibility with the built-in PHP web server
+    if ('/index.php' !== $_SERVER['SCRIPT_NAME'] && is_file(__DIR__.$_SERVER['SCRIPT_NAME'])) {
+        return false;
+    }
     umask(0000);
 
     Debug::enable();