diff --git a/src/Composer/Installer/InstallationManager.php b/src/Composer/Installer/InstallationManager.php
index ac59805fb..4bf207b76 100644
--- a/src/Composer/Installer/InstallationManager.php
+++ b/src/Composer/Installer/InstallationManager.php
@@ -51,6 +51,8 @@ class InstallationManager
      */
     public function getInstaller($type)
     {
+        $type = strtolower($type);
+
         if (isset($this->cache[$type])) {
             return $this->cache[$type];
         }