diff --git a/core/scripts/switch-psr4.sh b/core/scripts/switch-psr4.sh
index 07b68268b52e00be16453da02a751e96ac9dd82c..eb1a4803b1c7df6962221ce02821f8df3abfa2fc 100644
--- a/core/scripts/switch-psr4.sh
+++ b/core/scripts/switch-psr4.sh
@@ -201,6 +201,8 @@ function process_extension($name, $dir) {
   // Clean up.
   require_dir_empty("$dir/lib/Drupal");
   rmdir("$dir/lib/Drupal");
+  require_dir_empty("$dir/lib");
+  rmdir("$dir/lib");
 }
 
 /**