diff --git a/app/models/mixins/per_ems_worker_mixin.rb b/app/models/mixins/per_ems_worker_mixin.rb
index 93884f72c75..8fb69d3e1ff 100644
--- a/app/models/mixins/per_ems_worker_mixin.rb
+++ b/app/models/mixins/per_ems_worker_mixin.rb
@@ -18,7 +18,7 @@ def all_ems_in_zone
     end
 
     def all_valid_ems_in_zone
-      all_ems_in_zone.where(:enabled => true).select(&:authentication_status_ok?)
+      all_ems_in_zone.select {|e| e.enabled && e.authentication_status_ok?}
     end
 
     def desired_queue_names
diff --git a/spec/models/mixins/per_ems_worker_mixin_spec.rb b/spec/models/mixins/per_ems_worker_mixin_spec.rb
index 30e239ef545..bcc81c1a9a5 100644
--- a/spec/models/mixins/per_ems_worker_mixin_spec.rb
+++ b/spec/models/mixins/per_ems_worker_mixin_spec.rb
@@ -15,6 +15,14 @@
     expect(@worker_class.queue_name_for_ems(@ems)).to eq(@ems_queue_name)
   end
 
+  it ".all_valid_ems_in_zone" do
+    expect(@worker_class.all_valid_ems_in_zone).to be_empty
+
+    @ems.update(:enabled => true)
+    @ems.authentications.first.validation_successful
+    expect(@worker_class.all_valid_ems_in_zone).to eq([@ems])
+  end
+
   it "#worker_options" do
     expect(@worker_record.worker_options).to eq(:guid => @worker_record.guid, :ems_id => @ems.id)
   end