diff --git a/src/backends/native/meta-kms-update.c b/src/backends/native/meta-kms-update.c
index 68564fec7..f15ab3faa 100644
--- a/src/backends/native/meta-kms-update.c
+++ b/src/backends/native/meta-kms-update.c
@@ -844,6 +844,69 @@ merge_crtc_color_updates_from (MetaKmsUpdate *update,
     }
 }
 
+static GList *
+find_connector_update_link_for (MetaKmsUpdate    *update,
+                                MetaKmsConnector *connector)
+{
+  GList *l;
+
+  for (l = update->connector_updates; l; l = l->next)
+    {
+      MetaKmsConnectorUpdate *connector_update = l->data;
+
+      if (connector_update->connector == connector)
+        return l;
+    }
+
+  return NULL;
+}
+
+static void
+merge_connector_updates_from (MetaKmsUpdate *update,
+                              MetaKmsUpdate *other_update)
+{
+  while (other_update->connector_updates)
+    {
+      GList *l = other_update->connector_updates;
+      MetaKmsConnectorUpdate *other_connector_update = l->data;
+      MetaKmsConnector *connector = other_connector_update->connector;
+      GList *el;
+
+      other_update->connector_updates =
+        g_list_remove_link (other_update->connector_updates, l);
+      el = find_connector_update_link_for (update, connector);
+      if (el)
+        {
+          MetaKmsConnectorUpdate *connector_update = el->data;
+
+          if (other_connector_update->underscanning.has_update)
+            {
+              connector_update->underscanning =
+                other_connector_update->underscanning;
+            }
+
+          if (other_connector_update->privacy_screen.has_update)
+            {
+              connector_update->privacy_screen =
+                other_connector_update->privacy_screen;
+            }
+
+          if (other_connector_update->max_bpc.has_update)
+            {
+              connector_update->max_bpc =
+                other_connector_update->max_bpc;
+            }
+        }
+      else
+        {
+          update->connector_updates =
+            g_list_insert_before_link (update->connector_updates,
+                                       update->connector_updates,
+                                       l);
+        }
+    }
+}
+
 static void
 merge_custom_page_flip_from (MetaKmsUpdate *update,
                              MetaKmsUpdate *other_update)
@@ -880,12 +943,11 @@ meta_kms_update_merge_from (MetaKmsUpdate *update,
                             MetaKmsUpdate *other_update)
 {
   g_return_if_fail (update->device == other_update->device);
-  g_return_if_fail (!update->connector_updates &&
-                    !other_update->connector_updates);
 
   merge_mode_sets (update, other_update);
   merge_plane_assignments_from (update, other_update);
   merge_crtc_color_updates_from (update, other_update);
+  merge_connector_updates_from (update, other_update);
   merge_custom_page_flip_from (update, other_update);
   merge_page_flip_listeners_from (update, other_update);
   merge_result_listeners_from (update, other_update);
diff --git a/src/backends/native/meta-kms-update.h b/src/backends/native/meta-kms-update.h
index 885655c42..627d5f274 100644
--- a/src/backends/native/meta-kms-update.h
+++ b/src/backends/native/meta-kms-update.h
@@ -104,6 +104,7 @@ void meta_kms_update_free (MetaKmsUpdate *update);
 META_EXPORT_TEST
 MetaKmsDevice * meta_kms_update_get_device (MetaKmsUpdate *update);
 
+META_EXPORT_TEST
 void meta_kms_update_set_underscanning (MetaKmsUpdate    *update,
                                         MetaKmsConnector *connector,
                                         uint64_t          hborder,
@@ -112,10 +113,12 @@ void meta_kms_update_set_underscanning (MetaKmsUpdate    *update,
 void meta_kms_update_unset_underscanning (MetaKmsUpdate    *update,
                                           MetaKmsConnector *connector);
 
+META_EXPORT_TEST
 void meta_kms_update_set_privacy_screen (MetaKmsUpdate    *update,
                                          MetaKmsConnector *connector,
                                          gboolean          enabled);
 
+META_EXPORT_TEST
 void meta_kms_update_set_max_bpc (MetaKmsUpdate    *update,
                                   MetaKmsConnector *connector,
                                   uint64_t          max_bpc);
diff --git a/src/tests/native-kms-updates.c b/src/tests/native-kms-updates.c
index c7ed68157..92916aa3c 100644
--- a/src/tests/native-kms-updates.c
+++ b/src/tests/native-kms-updates.c
@@ -413,6 +413,8 @@ meta_test_kms_update_merge (void)
   GList *crtc_color_updates;
   MetaKmsCrtcColorUpdate *crtc_color_update;
   MetaGammaLut *crtc_gamma;
+  GList *connector_updates;
+  MetaKmsConnectorUpdate *connector_update;
 
   device = meta_get_test_kms_device (test_context);
   crtc = meta_get_test_kms_crtc (device);
@@ -455,6 +457,11 @@ meta_test_kms_update_merge (void)
   meta_kms_plane_assignment_set_cursor_hotspot (cursor_plane_assignment,
                                                 10, 11);
 
+  meta_kms_update_set_underscanning (update1,
+                                     connector,
+                                     123, 456);
+  meta_kms_update_set_privacy_screen (update1, connector, TRUE);
+
   /*
    * Create an update2 with a mode set and a cursor buffer 2
    * on the cursor plane at at (32, 56), and a new CRTC gamma.
@@ -486,6 +493,9 @@ meta_test_kms_update_merge (void)
   meta_kms_plane_assignment_set_cursor_hotspot (cursor_plane_assignment,
                                                 9, 7);
 
+  meta_kms_update_set_privacy_screen (update2, connector, FALSE);
+  meta_kms_update_set_max_bpc (update2, connector, 8);
+
   /*
    * Merge and check result.
    */
@@ -565,6 +575,22 @@ meta_test_kms_update_merge (void)
   g_assert_cmpuint (crtc_gamma->blue[1], ==, 8);
   g_assert_cmpuint (crtc_gamma->blue[2], ==, 9);
 
+  connector_updates = meta_kms_update_get_connector_updates (update1);
+  g_assert_cmpuint (g_list_length (connector_updates), ==, 1);
+  connector_update = connector_updates->data;
+  g_assert_nonnull (connector_update);
+
+  g_assert_true (connector_update->underscanning.has_update);
+  g_assert_true (connector_update->underscanning.is_active);
+  g_assert_cmpuint (connector_update->underscanning.hborder, ==, 123);
+  g_assert_cmpuint (connector_update->underscanning.vborder, ==, 456);
+
+  g_assert_true (connector_update->privacy_screen.has_update);
+  g_assert_false (connector_update->privacy_screen.is_enabled);
+
+  g_assert_true (connector_update->max_bpc.has_update);
+  g_assert_cmpuint (connector_update->max_bpc.value, ==, 8);
+
   meta_kms_update_free (update1);
 }