diff --git a/awesome.c b/awesome.c
index 4063a490e..bc73e337d 100644
--- a/awesome.c
+++ b/awesome.c
@@ -345,8 +345,7 @@ acquire_timestamp(void)
             atom, type, 8, 0, "");
     xcb_change_window_attributes(globalconf.connection, win,
             XCB_CW_EVENT_MASK, (uint32_t[]) { 0 });
-    xcb_ungrab_server(globalconf.connection);
-    xcb_flush(globalconf.connection);
+    xutil_ungrab_server(globalconf.connection);
 
     /* Now wait for the event */
     while((event = xcb_wait_for_event(globalconf.connection)))
@@ -882,8 +881,7 @@ main(int argc, char **argv)
                                  ROOT_WINDOW_EVENT_MASK);
 
     /* we will receive events, stop grabbing server */
-    xcb_ungrab_server(globalconf.connection);
-    xcb_flush(globalconf.connection);
+    xutil_ungrab_server(globalconf.connection);
 
     /* get the current wallpaper, from now on we are informed when it changes */
     root_update_wallpaper();
diff --git a/common/xutil.h b/common/xutil.h
index 5ee3b08de..81820f255 100644
--- a/common/xutil.h
+++ b/common/xutil.h
@@ -54,6 +54,20 @@ xutil_get_text_property_from_reply(xcb_get_property_reply_t *reply)
     return NULL;
 }
 
+static inline void
+xutil_ungrab_server(xcb_connection_t *connection)
+{
+    /* XCB's output buffer might have filled up between the GrabServer request
+     * and now. Thus, the GrabServer might already have been sent and the
+     * following UngrabServer would sit around in the output buffer for an
+     * indeterminate time and might cause problems. We cannot detect this
+     * situation, so just always flush directly after UngrabServer.
+     */
+    xcb_ungrab_server(connection);
+    xcb_flush(connection);
+}
+#define xcb_ungrab_server do_not_use_xcb_ungrab_server_directly
+
 uint16_t xutil_key_mask_fromstr(const char *);
 void xutil_key_mask_tostr(uint16_t, const char **, size_t *);
 
diff --git a/objects/client.c b/objects/client.c
index f00f586d8..f38e1626b 100644
--- a/objects/client.c
+++ b/objects/client.c
@@ -1241,7 +1241,7 @@ client_restore_enterleave_events(void)
     check(globalconf.pending_enter_leave_begin.sequence != 0);
     pair.begin = globalconf.pending_enter_leave_begin;
     pair.end = xcb_no_operation(globalconf.connection);
-    xcb_ungrab_server(globalconf.connection);
+    xutil_ungrab_server(globalconf.connection);
     globalconf.pending_enter_leave_begin.sequence = 0;
     sequence_pair_array_append(&globalconf.ignore_enter_leave_events, pair);
 }
@@ -1587,7 +1587,7 @@ client_manage(xcb_window_t w, xcb_get_geometry_reply_t *wgeom, xcb_get_window_at
                                  globalconf.screen->root,
                                  XCB_CW_EVENT_MASK,
                                  ROOT_WINDOW_EVENT_MASK);
-    xcb_ungrab_server(globalconf.connection);
+    xutil_ungrab_server(globalconf.connection);
 
     /* Do this now so that we don't get any events for the above
      * (Else, reparent could cause an UnmapNotify) */
@@ -1978,7 +1978,7 @@ client_set_minimized(lua_State *L, int cidx, bool s)
                                          c->window,
                                          XCB_CW_EVENT_MASK,
                                          client_select_input_val);
-            xcb_ungrab_server(globalconf.connection);
+            xutil_ungrab_server(globalconf.connection);
         }
         else
         {
diff --git a/root.c b/root.c
index ac5bb38b9..bc649c40a 100644
--- a/root.c
+++ b/root.c
@@ -124,8 +124,7 @@ root_set_wallpaper(cairo_pattern_t *pattern)
                                  globalconf.screen->root,
                                  XCB_CW_EVENT_MASK,
                                  ROOT_WINDOW_EVENT_MASK);
-    xcb_ungrab_server(globalconf.connection);
-    xcb_flush(globalconf.connection);
+    xutil_ungrab_server(globalconf.connection);
 
     /* Make sure our pixmap is not destroyed when we disconnect. */
     xcb_set_close_down_mode(c, XCB_CLOSE_DOWN_RETAIN_PERMANENT);