diff --git a/src/x11/events.c b/src/x11/events.c
index ef1301c1a..dc12b6e09 100644
--- a/src/x11/events.c
+++ b/src/x11/events.c
@@ -1314,15 +1314,17 @@ handle_other_xevent (MetaX11Display *x11_display,
   if (META_X11_DISPLAY_HAS_XSYNC (x11_display) &&
       event->type == (x11_display->xsync_event_base + XSyncAlarmNotify))
     {
-      MetaWindow *alarm_window = meta_x11_display_lookup_sync_alarm (x11_display,
-                                                                     ((XSyncAlarmNotifyEvent*)event)->alarm);
+      MetaSyncCounter *sync_counter;
 
-      if (alarm_window != NULL)
+      sync_counter = meta_x11_display_lookup_sync_alarm (x11_display,
+                                                         ((XSyncAlarmNotifyEvent*)event)->alarm);
+
+      if (sync_counter != NULL)
         {
           XSyncValue value = ((XSyncAlarmNotifyEvent*)event)->counter_value;
           gint64 new_counter_value;
           new_counter_value = XSyncValueLow32 (value) + ((gint64)XSyncValueHigh32 (value) << 32);
-          meta_window_x11_update_sync_request_counter (alarm_window, new_counter_value);
+          meta_sync_counter_update (sync_counter, new_counter_value);
           bypass_gtk = TRUE; /* GTK doesn't want to see this really */
         }
       else if (x11_display->alarm_filters)
diff --git a/src/x11/meta-sync-counter.c b/src/x11/meta-sync-counter.c
index 610035248..71bd89dbc 100644
--- a/src/x11/meta-sync-counter.c
+++ b/src/x11/meta-sync-counter.c
@@ -152,7 +152,7 @@ meta_sync_counter_create_sync_alarm (MetaSyncCounter *sync_counter)
     {
       meta_x11_display_register_sync_alarm (x11_display,
                                             &sync_counter->sync_request_alarm,
-                                            window);
+                                            sync_counter);
     }
   else
     {
diff --git a/src/x11/meta-x11-display-private.h b/src/x11/meta-x11-display-private.h
index f9a9f6203..1030a2947 100644
--- a/src/x11/meta-x11-display-private.h
+++ b/src/x11/meta-x11-display-private.h
@@ -37,6 +37,7 @@
 #include "meta-startup-notification-x11.h"
 #include "meta-x11-stack-private.h"
 #include "ui/ui.h"
+#include "x11/meta-sync-counter.h"
 
 typedef struct _MetaGroupPropHooks  MetaGroupPropHooks;
 typedef struct _MetaWindowPropHooks MetaWindowPropHooks;
@@ -109,6 +110,7 @@ struct _MetaX11Display
   Window composite_overlay_window;
 
   GHashTable *xids;
+  GHashTable *alarms;
 
   gboolean has_xinerama_indices;
 
@@ -211,11 +213,13 @@ void        meta_x11_display_register_x_window   (MetaX11Display *x11_display,
 void        meta_x11_display_unregister_x_window (MetaX11Display *x11_display,
                                                   Window          xwindow);
 
-MetaWindow *meta_x11_display_lookup_sync_alarm     (MetaX11Display *x11_display,
-                                                    XSyncAlarm      alarm);
-void        meta_x11_display_register_sync_alarm   (MetaX11Display *x11_display,
-                                                    XSyncAlarm     *alarmp,
-                                                    MetaWindow     *window);
+MetaSyncCounter * meta_x11_display_lookup_sync_alarm (MetaX11Display *x11_display,
+                                                      XSyncAlarm      alarm);
+
+void        meta_x11_display_register_sync_alarm (MetaX11Display  *x11_display,
+                                                  XSyncAlarm      *alarmp,
+                                                  MetaSyncCounter *sync_counter);
+
 void        meta_x11_display_unregister_sync_alarm (MetaX11Display *x11_display,
                                                     XSyncAlarm      alarm);
 
diff --git a/src/x11/meta-x11-display.c b/src/x11/meta-x11-display.c
index 69f9f901d..27e017de6 100644
--- a/src/x11/meta-x11-display.c
+++ b/src/x11/meta-x11-display.c
@@ -217,6 +217,8 @@ meta_x11_display_dispose (GObject *object)
       x11_display->xids = NULL;
     }
 
+  g_clear_pointer (&x11_display->alarms, g_hash_table_unref);
+
   if (x11_display->xroot != None)
     {
       unset_wm_check_hint (x11_display);
@@ -1311,6 +1313,8 @@ meta_x11_display_new (MetaDisplay  *display,
 
   x11_display->xids = g_hash_table_new (meta_unsigned_long_hash,
                                         meta_unsigned_long_equal);
+  x11_display->alarms = g_hash_table_new (meta_unsigned_long_hash,
+                                          meta_unsigned_long_equal);
 
   x11_display->groups_by_leader = NULL;
   x11_display->composite_overlay_window = None;
@@ -1700,36 +1704,30 @@ meta_x11_display_unregister_x_window (MetaX11Display *x11_display,
   g_hash_table_remove (x11_display->xids, &xwindow);
 }
 
-
-/* We store sync alarms in the window ID hash table, because they are
- * just more types of XIDs in the same global space, but we have
- * typesafe functions to register/unregister for readability.
- */
-
-MetaWindow *
+MetaSyncCounter *
 meta_x11_display_lookup_sync_alarm (MetaX11Display *x11_display,
                                     XSyncAlarm      alarm)
 {
-  return g_hash_table_lookup (x11_display->xids, &alarm);
+  return g_hash_table_lookup (x11_display->alarms, &alarm);
 }
 
 void
-meta_x11_display_register_sync_alarm (MetaX11Display *x11_display,
-                                      XSyncAlarm     *alarmp,
-                                      MetaWindow     *window)
+meta_x11_display_register_sync_alarm (MetaX11Display  *x11_display,
+                                      XSyncAlarm      *alarmp,
+                                      MetaSyncCounter *sync_counter)
 {
-  g_return_if_fail (g_hash_table_lookup (x11_display->xids, alarmp) == NULL);
+  g_return_if_fail (g_hash_table_lookup (x11_display->alarms, alarmp) == NULL);
 
-  g_hash_table_insert (x11_display->xids, alarmp, window);
+  g_hash_table_insert (x11_display->alarms, alarmp, sync_counter);
 }
 
 void
 meta_x11_display_unregister_sync_alarm (MetaX11Display *x11_display,
                                         XSyncAlarm      alarm)
 {
-  g_return_if_fail (g_hash_table_lookup (x11_display->xids, &alarm) != NULL);
+  g_return_if_fail (g_hash_table_lookup (x11_display->alarms, &alarm) != NULL);
 
-  g_hash_table_remove (x11_display->xids, &alarm);
+  g_hash_table_remove (x11_display->alarms, &alarm);
 }
 
 MetaX11AlarmFilter *
diff --git a/src/x11/window-x11.c b/src/x11/window-x11.c
index 6b82d16b8..738e28780 100644
--- a/src/x11/window-x11.c
+++ b/src/x11/window-x11.c
@@ -4123,16 +4123,6 @@ meta_window_x11_destroy_sync_request_alarm (MetaWindow *window)
   meta_sync_counter_destroy_sync_alarm (&priv->sync_counter);
 }
 
-void
-meta_window_x11_update_sync_request_counter (MetaWindow *window,
-                                             gint64      new_counter_value)
-{
-  MetaWindowX11 *window_x11 = META_WINDOW_X11 (window);
-  MetaWindowX11Private *priv = meta_window_x11_get_instance_private (window_x11);
-
-  meta_sync_counter_update (&priv->sync_counter, new_counter_value);
-}
-
 Window
 meta_window_x11_get_toplevel_xwindow (MetaWindow *window)
 {
diff --git a/src/x11/window-x11.h b/src/x11/window-x11.h
index 8193fea3a..5581747ff 100644
--- a/src/x11/window-x11.h
+++ b/src/x11/window-x11.h
@@ -62,8 +62,6 @@ void meta_window_x11_set_allowed_actions_hint    (MetaWindow *window);
 
 void meta_window_x11_create_sync_request_alarm   (MetaWindow *window);
 void meta_window_x11_destroy_sync_request_alarm  (MetaWindow *window);
-void meta_window_x11_update_sync_request_counter (MetaWindow *window,
-                                                  gint64      new_counter_value);
 
 void meta_window_x11_update_input_region         (MetaWindow *window);
 void meta_window_x11_update_shape_region         (MetaWindow *window);