diff --git a/src/Bridges/ApplicationDI/ApplicationExtension.php b/src/Bridges/ApplicationDI/ApplicationExtension.php
index fc887632c..954a565da 100644
--- a/src/Bridges/ApplicationDI/ApplicationExtension.php
+++ b/src/Bridges/ApplicationDI/ApplicationExtension.php
@@ -9,8 +9,6 @@
 
 use Nette;
 use Nette\Application\UI;
-use Tracy;
-use Composer\Autoload\ClassLoader;
 
 
 /**
@@ -41,7 +39,7 @@ class ApplicationExtension extends Nette\DI\CompilerExtension
 
 	public function __construct($debugMode = FALSE, array $scanDirs = NULL, $tempDir = NULL)
 	{
-		$this->defaults['debugger'] = class_exists('Tracy\IBarPanel');
+		$this->defaults['debugger'] = interface_exists('Tracy\IBarPanel');
 		$this->defaults['scanDirs'] = (array) $scanDirs;
 		$this->defaults['scanComposer'] = class_exists('Composer\Autoload\ClassLoader');
 		$this->defaults['catchExceptions'] = !$debugMode;
diff --git a/src/Bridges/ApplicationDI/RoutingExtension.php b/src/Bridges/ApplicationDI/RoutingExtension.php
index 8b8aa5d79..ea594d146 100644
--- a/src/Bridges/ApplicationDI/RoutingExtension.php
+++ b/src/Bridges/ApplicationDI/RoutingExtension.php
@@ -8,7 +8,6 @@
 namespace Nette\Bridges\ApplicationDI;
 
 use Nette;
-use Tracy;
 
 
 /**
@@ -28,7 +27,7 @@ class RoutingExtension extends Nette\DI\CompilerExtension
 
 	public function __construct($debugMode = FALSE)
 	{
-		$this->defaults['debugger'] = class_exists('Tracy\IBarPanel');
+		$this->defaults['debugger'] = interface_exists('Tracy\IBarPanel');
 		$this->debugMode = $debugMode;
 	}