diff --git a/composer.json b/composer.json
index ff99d429e0e9c47f52bf8353aa9490dd5082c08b..a367d0ba534358dd8472864ef7cb47cf470843c9 100644
--- a/composer.json
+++ b/composer.json
@@ -104,6 +104,9 @@
       "web/themes/contrib/{$name}": [
         "type:drupal-theme"
       ],
+      "web/themes/custom/{$name}": [
+        "type:drupal-custom-theme"
+      ],
       "drush/contrib/{$name}": [
         "type:drupal-drush"
       ]