diff --git a/tests/unit/plugins/modules/fixtures/pfsense_interface_config.xml b/tests/unit/plugins/modules/fixtures/pfsense_interface_config.xml
index 752e35d7..9c736a31 100644
--- a/tests/unit/plugins/modules/fixtures/pfsense_interface_config.xml
+++ b/tests/unit/plugins/modules/fixtures/pfsense_interface_config.xml
@@ -146,6 +146,14 @@
 			<ipaddr>172.16.151.210</ipaddr>
 			<subnet>24</subnet>
 		</opt3>
+		<opt4>
+			<descr>lan_1200</descr>
+			<if>vmx1.1200</if>
+			<enable></enable>
+			<spoofmac></spoofmac>
+			<ipaddr>172.16.152.210</ipaddr>
+			<subnet>24</subnet>
+		</opt4>
 		<opt5>
 			<if>vmx4</if>
 			<descr>vt2</descr>
diff --git a/tests/unit/plugins/modules/test_pfsense_interface.py b/tests/unit/plugins/modules/test_pfsense_interface.py
index b10cd21d..9259c3d5 100644
--- a/tests/unit/plugins/modules/test_pfsense_interface.py
+++ b/tests/unit/plugins/modules/test_pfsense_interface.py
@@ -276,6 +276,12 @@ def test_interface_error_inet6_overlaps2(self):
         msg = "IP address 2001::2001/56 is being used by or overlaps with: lan (2001::2001:22/64)"
         self.do_module_test(interface, failed=True, msg=msg)
 
+    def test_interface_delete_sub(self):
+        """ test delete sub interface """
+        interface = dict(descr='lan_1200', interface='vmx1.1200', state='absent')
+        command = "delete interface 'lan_1200'"
+        self.do_module_test(interface, delete=True, command=command)
+
     def test_interface_error_not_uniq(self):
         """ test creation of a new interface with interface_descr """
         interface = dict(descr='VOICE', interface_descr='notuniq')