diff --git a/src/Symfony/Component/Config/Definition/Builder/TreeBuilder.php b/src/Symfony/Component/Config/Definition/Builder/TreeBuilder.php
index 6da510ec1c2d..6b4323d42f51 100644
--- a/src/Symfony/Component/Config/Definition/Builder/TreeBuilder.php
+++ b/src/Symfony/Component/Config/Definition/Builder/TreeBuilder.php
@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Config\Definition\Builder;
 
+use Symfony\Component\Config\Definition\Exception\TreeWithoutRootNodeException;
 use Symfony\Component\Config\Definition\NodeInterface;
 
 /**
@@ -74,7 +75,7 @@ public function setPathSeparator(string $separator)
     private function assertTreeHasRootNode()
     {
         if (null === $this->root) {
-            throw new \RuntimeException('The configuration tree has no root node.');
+            throw new TreeWithoutRootNodeException('The configuration tree has no root node.');
         }
     }
 }
diff --git a/src/Symfony/Component/Config/Definition/Exception/TreeWithoutRootNodeException.php b/src/Symfony/Component/Config/Definition/Exception/TreeWithoutRootNodeException.php
new file mode 100644
index 000000000000..67b0c4bb2e08
--- /dev/null
+++ b/src/Symfony/Component/Config/Definition/Exception/TreeWithoutRootNodeException.php
@@ -0,0 +1,19 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Config\Definition\Exception;
+
+/**
+ * @author Roland Franssen <franssen.roland@gmail.com>
+ */
+class TreeWithoutRootNodeException extends \RuntimeException
+{
+}
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/ValidateEnvPlaceholdersPass.php b/src/Symfony/Component/DependencyInjection/Compiler/ValidateEnvPlaceholdersPass.php
index 09c83ce3bf2e..58fc95b5fc55 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/ValidateEnvPlaceholdersPass.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/ValidateEnvPlaceholdersPass.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\DependencyInjection\Compiler;
 
 use Symfony\Component\Config\Definition\BaseNode;
+use Symfony\Component\Config\Definition\Exception\TreeWithoutRootNodeException;
 use Symfony\Component\Config\Definition\Processor;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Extension\ConfigurationExtensionInterface;
@@ -75,7 +76,10 @@ public function process(ContainerBuilder $container)
                     continue;
                 }
 
-                $processor->processConfiguration($configuration, $config);
+                try {
+                    $processor->processConfiguration($configuration, $config);
+                } catch (TreeWithoutRootNodeException $e) {
+                }
             }
         } finally {
             BaseNode::resetPlaceholders();
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
index 9534b11a90bb..0fb2f6dc91a4 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/ValidateEnvPlaceholdersPassTest.php
@@ -14,6 +14,7 @@
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\Config\Definition\Builder\TreeBuilder;
 use Symfony\Component\Config\Definition\ConfigurationInterface;
+use Symfony\Component\Config\Definition\Exception\TreeWithoutRootNodeException;
 use Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationPass;
 use Symfony\Component\DependencyInjection\Compiler\RegisterEnvVarProcessorsPass;
 use Symfony\Component\DependencyInjection\Compiler\ValidateEnvPlaceholdersPass;
@@ -222,6 +223,17 @@ public function testEnvWithVariableNode(): void
         $this->assertSame($expected, $container->resolveEnvPlaceholders($ext->getConfig()));
     }
 
+    public function testConfigurationWithoutRootNode(): void
+    {
+        $container = new ContainerBuilder();
+        $container->registerExtension($ext = new EnvExtension(new EnvConfigurationWithoutRootNode()));
+        $container->loadFromExtension('env_extension');
+
+        $this->doProcess($container);
+
+        $this->addToAssertionCount(1);
+    }
+
     private function doProcess(ContainerBuilder $container): void
     {
         (new MergeExtensionConfigurationPass())->process($container);
@@ -267,10 +279,24 @@ public function getConfigTreeBuilder()
     }
 }
 
+class EnvConfigurationWithoutRootNode implements ConfigurationInterface
+{
+    public function getConfigTreeBuilder()
+    {
+        return new TreeBuilder();
+    }
+}
+
 class EnvExtension extends Extension
 {
+    private $configuration;
     private $config;
 
+    public function __construct(ConfigurationInterface $configuration = null)
+    {
+        $this->configuration = $configuration ?? new EnvConfiguration();
+    }
+
     public function getAlias()
     {
         return 'env_extension';
@@ -278,12 +304,16 @@ public function getAlias()
 
     public function getConfiguration(array $config, ContainerBuilder $container)
     {
-        return new EnvConfiguration();
+        return $this->configuration;
     }
 
     public function load(array $configs, ContainerBuilder $container)
     {
-        $this->config = $this->processConfiguration($this->getConfiguration($configs, $container), $configs);
+        try {
+            $this->config = $this->processConfiguration($this->getConfiguration($configs, $container), $configs);
+        } catch (TreeWithoutRootNodeException $e) {
+            $this->config = null;
+        }
     }
 
     public function getConfig()