diff --git a/app/models/service.rb b/app/models/service.rb
index 4fc349f8b717..1f5be83d3065 100644
--- a/app/models/service.rb
+++ b/app/models/service.rb
@@ -185,7 +185,7 @@ def direct_vms
   end
 
   def all_vms
-    MiqPreloader.preload_and_map(subtree, :direct_vms)
+    MiqPreloader.preload(subtree, :direct_vms).flat_map(&:direct_vms)
   end
 
   def vms