diff --git a/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php b/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
index 4ee40def66b1..7c12b7015e62 100644
--- a/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
+++ b/src/Symfony/Bridge/ProxyManager/LazyProxy/PhpDumper/ProxyDumper.php
@@ -47,7 +47,7 @@ public function __construct($salt = '')
      */
     public function isProxyCandidate(Definition $definition)
     {
-        return $definition->isLazy() && ($class = $definition->getClass()) && class_exists($class);
+        return $definition->isLazy() && ($class = $definition->getClass()) && (class_exists($class) || interface_exists($class));
     }
 
     /**
diff --git a/src/Symfony/Bridge/ProxyManager/Tests/LazyProxy/PhpDumper/ProxyDumperTest.php b/src/Symfony/Bridge/ProxyManager/Tests/LazyProxy/PhpDumper/ProxyDumperTest.php
index 2f7ee38cce2a..f0822d461642 100644
--- a/src/Symfony/Bridge/ProxyManager/Tests/LazyProxy/PhpDumper/ProxyDumperTest.php
+++ b/src/Symfony/Bridge/ProxyManager/Tests/LazyProxy/PhpDumper/ProxyDumperTest.php
@@ -15,6 +15,7 @@
 use Symfony\Bridge\ProxyManager\LazyProxy\PhpDumper\ProxyDumper;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\DependencyInjection\LazyProxy\PhpDumper\DumperInterface;
 
 /**
  * Tests for {@see \Symfony\Bridge\ProxyManager\LazyProxy\PhpDumper\ProxyDumper}.
@@ -137,6 +138,7 @@ public function getProxyCandidates()
         $definitions = [
             [new Definition(__CLASS__), true],
             [new Definition('stdClass'), true],
+            [new Definition(DumperInterface::class), true],
             [new Definition(uniqid('foo', true)), false],
             [new Definition(), false],
         ];