diff --git a/ironic/drivers/modules/ilo/inspect.py b/ironic/drivers/modules/ilo/inspect.py
index 0df53b26dd..a81fb91443 100644
--- a/ironic/drivers/modules/ilo/inspect.py
+++ b/ironic/drivers/modules/ilo/inspect.py
@@ -155,6 +155,9 @@ def _update_capabilities(node, new_capabilities):
     :returns: The capability string after adding/updating the
               node_capabilities with new_capabilities
     :raises: InvalidParameterValue, if node_capabilities is malformed.
+    :raises: HardwareInspectionFailure, if inspected capabilities
+             are not in dictionary format.
+
     """
     cap_dict = {}
     node_capabilities = node.properties.get('capabilities')
@@ -171,12 +174,12 @@ def _update_capabilities(node, new_capabilities):
                     "properties['capabilities'] string")
                     % {'node': node.uuid, 'capabilities': node_capabilities})
             raise exception.InvalidParameterValue(msg)
-    if new_capabilities and isinstance(new_capabilities, dict):
+    if isinstance(new_capabilities, dict):
         cap_dict.update(new_capabilities)
     else:
         msg = (_("The expected format of capabilities from inspection "
                  "is dictionary while node %(node)s returned "
-                 "%(capabilities)s."), {'node': node.uuid,
+                 "%(capabilities)s.") % {'node': node.uuid,
                  'capabilities': new_capabilities})
         raise exception.HardwareInspectionFailure(error=msg)
     return ','.join(['%(key)s:%(value)s' % {'key': key, 'value': value}
@@ -229,7 +232,6 @@ def _get_macs_for_desired_ports(node, macs):
         to_be_created_macs = macs
     else:
         to_be_created_macs = {}
-        # desired_macs_list = desired_macs.split(',')
         # The list should look like ['Port 1', 'Port 2'] as
         # iLO returns port numbers like this.
         desired_macs_list = [
diff --git a/ironic/tests/drivers/ilo/test_inspect.py b/ironic/tests/drivers/ilo/test_inspect.py
index 505f0f1437..129f52b0fc 100644
--- a/ironic/tests/drivers/ilo/test_inspect.py
+++ b/ironic/tests/drivers/ilo/test_inspect.py
@@ -483,7 +483,9 @@ class TestInspectPrivateMethods(db_base.DbTestCase):
         cap_string = 'ilo_firmware_version:xyz,foo:bar,somekey:value'
         cap_returned = ilo_inspect._update_capabilities(self.node,
                                                         capabilities)
-        self.assertEqual(sorted(cap_string), sorted(cap_returned))
+        set1 = set(cap_string.split(','))
+        set2 = set(cap_returned.split(','))
+        self.assertEqual(set1, set2)
         self.assertIsInstance(cap_returned, str)
 
     def test__update_capabilities_invalid_capabilities(self):
@@ -498,6 +500,30 @@ class TestInspectPrivateMethods(db_base.DbTestCase):
                           ilo_inspect._update_capabilities,
                           self.node, capabilities)
 
+    def test__update_capabilities_add_to_existing_capabilities(self):
+        node_capabilities = {'capabilities': 'foo:bar'}
+        self.node.properties.update(node_capabilities)
+        new_capabilities = {'BootMode': 'uefi'}
+        expected_capabilities = 'BootMode:uefi,foo:bar'
+        cap_returned = ilo_inspect._update_capabilities(self.node,
+                                                        new_capabilities)
+        set1 = set(expected_capabilities.split(','))
+        set2 = set(cap_returned.split(','))
+        self.assertEqual(set1, set2)
+        self.assertIsInstance(cap_returned, str)
+
+    def test__update_capabilities_replace_to_existing_capabilities(self):
+        node_capabilities = {'capabilities': 'BootMode:uefi'}
+        self.node.properties.update(node_capabilities)
+        new_capabilities = {'BootMode': 'bios'}
+        expected_capabilities = 'BootMode:bios'
+        cap_returned = ilo_inspect._update_capabilities(self.node,
+                                                        new_capabilities)
+        set1 = set(expected_capabilities.split(','))
+        set2 = set(cap_returned.split(','))
+        self.assertEqual(set1, set2)
+        self.assertIsInstance(cap_returned, str)
+
     def test__get_macs_for_desired_ports(self):
         driver_info_mock = {'inspect_ports': '1,2'}
         self.node.driver_info = driver_info_mock