diff --git a/app/models/ext_management_system.rb b/app/models/ext_management_system.rb
index 53713330dc6..746a9cf5a2f 100644
--- a/app/models/ext_management_system.rb
+++ b/app/models/ext_management_system.rb
@@ -49,7 +49,7 @@ def self.api_allowed_attributes
   has_many :hardwares,         :through => :vms_and_templates
   has_many :networks,          :through => :hardwares
   has_many :disks,             :through => :hardwares
-  has_many :physical_servers,  :foreign_key => :ems_id, :inverse_of => :ext_management_system
+  has_many :physical_servers,  :foreign_key => :ems_id, :inverse_of => :ext_management_system, :dependent => :destroy
 
   has_many :storages,       -> { distinct },          :through => :hosts
   has_many :ems_events,     -> { order("timestamp") }, :class_name => "EmsEvent",    :foreign_key => "ems_id",
diff --git a/app/models/physical_server.rb b/app/models/physical_server.rb
index ce3dcfa5ffe..17edc56683d 100644
--- a/app/models/physical_server.rb
+++ b/app/models/physical_server.rb
@@ -27,7 +27,7 @@ class PhysicalServer < ApplicationRecord
   has_one :host, :inverse_of => :physical_server
   has_one :asset_detail, :as => :resource, :dependent => :destroy
   has_many :guest_devices, :through => :hardware
-  has_many :miq_alert_statuses, :as => :resource, :dependent => :destroy
+  has_many :miq_alert_statuses, :as => :resource, :dependent => :destroy, :inverse_of => :physical_server
 
   scope :with_hosts, -> { where("physical_servers.id in (select hosts.physical_server_id from hosts)") }