diff --git a/lib/netbox_client_ruby/api/ipam/ip_address.rb b/lib/netbox_client_ruby/api/ipam/ip_address.rb
index 152115c..16cd5ed 100644
--- a/lib/netbox_client_ruby/api/ipam/ip_address.rb
+++ b/lib/netbox_client_ruby/api/ipam/ip_address.rb
@@ -38,7 +38,7 @@ def interface
 
         return nil unless interface_data
 
-        if interface_data.key? ('virtual_machine')
+        if interface_data.key? ('virtual_machine') and not interface_data['virtual_machine'].nil?
           Virtualization::Interface.new interface_data['id']
         else
           DCIM::Interface.new interface_data['id']