diff --git a/src/Composer/Installer/PluginInstaller.php b/src/Composer/Installer/PluginInstaller.php
index ddb8e5bdd..55945c671 100644
--- a/src/Composer/Installer/PluginInstaller.php
+++ b/src/Composer/Installer/PluginInstaller.php
@@ -27,7 +27,6 @@ use Composer\Package\PackageInterface;
 class PluginInstaller extends LibraryInstaller
 {
     private $installationManager;
-    private static $classCounter = 0;
 
     /**
      * Initializes Plugin installer.