diff --git a/src/Symfony/Component/ErrorHandler/DebugClassLoader.php b/src/Symfony/Component/ErrorHandler/DebugClassLoader.php
index 36fb2ded75..0668489104 100644
--- a/src/Symfony/Component/ErrorHandler/DebugClassLoader.php
+++ b/src/Symfony/Component/ErrorHandler/DebugClassLoader.php
@@ -15,6 +15,7 @@ use Composer\InstalledVersions;
 use Doctrine\Common\Persistence\Proxy as LegacyProxy;
 use Doctrine\Persistence\Proxy;
 use Mockery\MockInterface;
+use Phake\IMock;
 use PHPUnit\Framework\MockObject\Matcher\StatelessInvocation;
 use PHPUnit\Framework\MockObject\MockObject;
 use Prophecy\Prophecy\ProphecySubjectInterface;
@@ -310,6 +311,7 @@ class DebugClassLoader
                     && !is_subclass_of($symbols[$i], ProxyInterface::class)
                     && !is_subclass_of($symbols[$i], LegacyProxy::class)
                     && !is_subclass_of($symbols[$i], MockInterface::class)
+                    && !is_subclass_of($symbols[$i], IMock::class)
                 ) {
                     $loader->checkClass($symbols[$i]);
                 }