diff --git a/src/backends/meta-monitor-manager-dummy.c b/src/backends/meta-monitor-manager-dummy.c
index ca3d200a7..2516d51ae 100644
--- a/src/backends/meta-monitor-manager-dummy.c
+++ b/src/backends/meta-monitor-manager-dummy.c
@@ -96,7 +96,7 @@ create_mode (CrtcModeSpec *spec,
   crtc_mode_info->refresh_rate = spec->refresh_rate;
 
   return g_object_new (META_TYPE_CRTC_MODE,
-                       "id", mode_id,
+                       "id", (uint64_t) mode_id,
                        "info", crtc_mode_info,
                        NULL);
 }
@@ -205,7 +205,7 @@ append_monitor (MetaMonitorManager *manager,
   *modes = g_list_concat (*modes, new_modes);
 
   crtc = g_object_new (META_TYPE_CRTC_DUMMY,
-                       "id", g_list_length (*crtcs) + 1,
+                       "id", (uint64_t) g_list_length (*crtcs) + 1,
                        "gpu", gpu,
                        NULL);
   *crtcs = g_list_append (*crtcs, crtc);
@@ -237,7 +237,7 @@ append_monitor (MetaMonitorManager *manager,
   output_info->n_possible_crtcs = 1;
 
   output = g_object_new (META_TYPE_OUTPUT_DUMMY,
-                         "id", number,
+                         "id", (uint64_t) number,
                          "gpu", gpu,
                          "info", output_info,
                          NULL);
@@ -291,7 +291,7 @@ append_tiled_monitor (MetaMonitorManager *manager,
       MetaCrtc *crtc;
 
       crtc = g_object_new (META_TYPE_CRTC_DUMMY,
-                           "id", g_list_length (*crtcs) + i + 1,
+                           "id", (uint64_t) g_list_length (*crtcs) + i + 1,
                            "gpu", gpu,
                            NULL);
       new_crtcs = g_list_append (new_crtcs, crtc);
@@ -358,7 +358,7 @@ append_tiled_monitor (MetaMonitorManager *manager,
       output_info->n_possible_crtcs = n_tiles;
 
       output = g_object_new (META_TYPE_OUTPUT_DUMMY,
-                             "id", number,
+                             "id", (uint64_t) number,
                              "gpu", gpu,
                              "info", output_info,
                              NULL);
diff --git a/src/backends/native/meta-crtc-kms.c b/src/backends/native/meta-crtc-kms.c
index ed799cd65..de13905a7 100644
--- a/src/backends/native/meta-crtc-kms.c
+++ b/src/backends/native/meta-crtc-kms.c
@@ -291,7 +291,7 @@ meta_crtc_kms_new (MetaGpuKms  *gpu_kms,
   primary_plane = meta_kms_device_get_primary_plane_for (kms_device,
                                                          kms_crtc);
   crtc_kms = g_object_new (META_TYPE_CRTC_KMS,
-                           "id", meta_kms_crtc_get_id (kms_crtc),
+                           "id", (uint64_t) meta_kms_crtc_get_id (kms_crtc),
                            "gpu", gpu,
                            NULL);
 
diff --git a/src/backends/x11/meta-crtc-xrandr.c b/src/backends/x11/meta-crtc-xrandr.c
index b03e73c83..9f60a0d50 100644
--- a/src/backends/x11/meta-crtc-xrandr.c
+++ b/src/backends/x11/meta-crtc-xrandr.c
@@ -244,7 +244,7 @@ meta_crtc_xrandr_new (MetaGpuXrandr      *gpu_xrandr,
   all_transforms =
     meta_monitor_transform_from_xrandr_all (xrandr_crtc->rotations);
   crtc_xrandr = g_object_new (META_TYPE_CRTC_XRANDR,
-                              "id", crtc_id,
+                              "id", (uint64_t) crtc_id,
                               "gpu", gpu,
                               "all-transforms", all_transforms,
                               NULL);
diff --git a/src/backends/x11/meta-gpu-xrandr.c b/src/backends/x11/meta-gpu-xrandr.c
index 5f6bc7894..bc3292d36 100644
--- a/src/backends/x11/meta-gpu-xrandr.c
+++ b/src/backends/x11/meta-gpu-xrandr.c
@@ -154,7 +154,7 @@ meta_gpu_xrandr_read_current (MetaGpu  *gpu,
 
       crtc_mode_name = get_xmode_name (xmode);
       mode = g_object_new (META_TYPE_CRTC_MODE,
-                           "id", xmode->id,
+                           "id", (uint64_t) xmode->id,
                            "name", crtc_mode_name,
                            "info", crtc_mode_info,
                            NULL);
diff --git a/src/backends/x11/meta-output-xrandr.c b/src/backends/x11/meta-output-xrandr.c
index 49fa838db..3a85cb7aa 100644
--- a/src/backends/x11/meta-output-xrandr.c
+++ b/src/backends/x11/meta-output-xrandr.c
@@ -871,7 +871,7 @@ meta_output_xrandr_new (MetaGpuXrandr *gpu_xrandr,
   output_info_init_backlight_limits_xrandr (output_info, xdisplay, output_id);
 
   output = g_object_new (META_TYPE_OUTPUT_XRANDR,
-                         "id", output_id,
+                         "id", (uint64_t) output_id,
                          "gpu", gpu_xrandr,
                          "info", output_info,
                          NULL);
diff --git a/src/tests/headless-start-test.c b/src/tests/headless-start-test.c
index 075b9b809..027dd9cb7 100644
--- a/src/tests/headless-start-test.c
+++ b/src/tests/headless-start-test.c
@@ -137,14 +137,14 @@ meta_test_headless_monitor_connect (void)
   crtc_mode_info->refresh_rate = 60.0;
 
   crtc_mode = g_object_new (META_TYPE_CRTC_MODE,
-                            "id", 1,
+                            "id", (uint64_t) 1,
                             "info", crtc_mode_info,
                             NULL);
   test_setup->modes = g_list_append (NULL, crtc_mode);
 
   gpu = META_GPU (meta_backend_get_gpus (meta_get_backend ())->data);
   crtc = g_object_new (META_TYPE_CRTC_TEST,
-                       "id", 1,
+                       "id", (uint64_t) 1,
                        "gpu", gpu,
                        NULL);
   test_setup->crtcs = g_list_append (NULL, crtc);
@@ -169,7 +169,7 @@ meta_test_headless_monitor_connect (void)
   output_info->connector_type = META_CONNECTOR_TYPE_DisplayPort;
 
   output = g_object_new (META_TYPE_OUTPUT_TEST,
-                         "id", 1,
+                         "id", (uint64_t) 1,
                          "gpu", gpu,
                          "info", output_info,
                          NULL);
diff --git a/src/tests/monitor-test-utils.c b/src/tests/monitor-test-utils.c
index 3752a6537..a83d8c8e2 100644
--- a/src/tests/monitor-test-utils.c
+++ b/src/tests/monitor-test-utils.c
@@ -556,7 +556,7 @@ create_monitor_test_setup (MonitorTestCaseSetup *setup,
       crtc_mode_info->flags = setup->modes[i].flags;
 
       mode = g_object_new (META_TYPE_CRTC_MODE,
-                           "id", i,
+                           "id", (uint64_t) i,
                            "info", crtc_mode_info,
                            NULL);
 
@@ -569,7 +569,7 @@ create_monitor_test_setup (MonitorTestCaseSetup *setup,
       MetaCrtc *crtc;
 
       crtc = g_object_new (META_TYPE_CRTC_TEST,
-                           "id", i + 1,
+                           "id", (uint64_t) i + 1,
                            "gpu", test_get_gpu (),
                            NULL);
 
@@ -676,7 +676,7 @@ create_monitor_test_setup (MonitorTestCaseSetup *setup,
         setup->outputs[i].panel_orientation_transform;
 
       output = g_object_new (META_TYPE_OUTPUT_TEST,
-                             "id", i,
+                             "id", (uint64_t) i,
                              "gpu", test_get_gpu (),
                              "info", output_info,
                              NULL);