diff --git a/src/Roundcube/Composer/RoundcubeInstaller.php b/src/Roundcube/Composer/RoundcubeInstaller.php
index 1117286..5ae77ed 100644
--- a/src/Roundcube/Composer/RoundcubeInstaller.php
+++ b/src/Roundcube/Composer/RoundcubeInstaller.php
@@ -22,7 +22,7 @@ public function activate(Composer $composer, IOInterface $io)
 
     public function deactivate(Composer $composer, IOInterface $io)
     {
-        foreach ($installers as $installer) {
+        foreach ($this->installers as $installer) {
             $composer->getInstallationManager()->removeInstaller($installer);
         }
     }