diff --git a/src/action/client.h b/src/action/client.h
index 4a1f72c2..11ec5866 100644
--- a/src/action/client.h
+++ b/src/action/client.h
@@ -140,9 +140,6 @@ void client_focus_group_member(Client *c) {
 	if (c->isgroupfocusing)
 		return;
 
-	if (c->mon->isoverview)
-		return;
-
 	Client *head = c;
 	while (head->group_prev)
 		head = head->group_prev;
@@ -156,12 +153,16 @@ void client_focus_group_member(Client *c) {
 		head = head->group_next;
 	}
 
-	if (cur_focusing) {
-		cur_focusing->isgroupfocusing = false;
-		c->mon = cur_focusing->mon;
-		client_replace(c, cur_focusing, true);
-		mango_group_bar_set_focus(cur_focusing->group_bar, false);
-	}
+	if (!cur_focusing || !cur_focusing->mon)
+		return;
+
+	if (cur_focusing && cur_focusing->mon->isoverview)
+		return;
+
+	cur_focusing->isgroupfocusing = false;
+	c->mon = cur_focusing->mon;
+	client_replace(c, cur_focusing, true);
+	mango_group_bar_set_focus(cur_focusing->group_bar, false);
 
 	c->isgroupfocusing = true;
 	mango_group_bar_set_focus(c->group_bar, true);
@@ -255,4 +256,16 @@ void client_handle_decorate_click(MangoGroupBar *gb) {
 		Client *c = gb->node_data;
 		client_focus_group_member(c);
 	}
+}
+
+void client_set_group_mon(Client *c, Monitor *m) {
+	Client *head = c;
+	while (head->group_prev)
+		head = head->group_prev;
+
+	Client *cur = head;
+	while (cur) {
+		cur->mon = m;
+		cur = cur->group_next;
+	}
 }
\ No newline at end of file
diff --git a/src/dispatch/bind_define.h b/src/dispatch/bind_define.h
index 607708a4..f2a73230 100644
--- a/src/dispatch/bind_define.h
+++ b/src/dispatch/bind_define.h
@@ -162,38 +162,50 @@ int32_t groupjoin(const Arg *arg) {
 	if (!selmon)
 		return 0;
 
-	Client *need_join_client = arg->tc ? arg->tc : selmon->sel;
-	if (!need_join_client)
-		return 0;
+	Monitor *oldmon = NULL;
 
-	if (need_join_client->group_next || need_join_client->group_prev) {
+	Client *need_join_client = arg->tc ? arg->tc : selmon->sel;
+	if (!need_join_client || !need_join_client->mon)
 		return 0;
-	}
 
 	Client *need_replace_client = NULL;
 	need_replace_client = direction_select(arg);
 
-	if (!need_replace_client ||
-		need_replace_client->mon != need_join_client->mon)
+	if (!need_replace_client || !need_replace_client->mon)
 		return 0;
 
-	if (!need_join_client->group_next && !need_join_client->group_prev) {
-
-		if (!need_replace_client->group_prev &&
-			!need_replace_client->group_next) {
-			need_replace_client->isgroupfocusing = true;
-		}
-
-		need_join_client->group_next = need_replace_client;
-		if (need_replace_client->group_prev) {
-			need_replace_client->group_prev->group_next = need_join_client;
-		}
-		need_join_client->group_prev = need_replace_client->group_prev;
-		need_replace_client->group_prev = need_join_client;
-
-		client_focus_group_member(need_join_client);
-		arrange(need_join_client->mon, false, false);
+	if (need_join_client == need_replace_client)
 		return 0;
+
+	if (need_join_client->group_next || need_join_client->group_prev) {
+		groupleave(&(Arg){.tc = need_join_client});
+	}
+
+	if (need_join_client->mon != need_replace_client->mon) {
+		oldmon = need_join_client->mon;
+		need_join_client->mon = need_replace_client->mon;
+	}
+
+	if (!need_replace_client->group_prev && !need_replace_client->group_next) {
+		need_replace_client->isgroupfocusing = true;
+	}
+
+	need_join_client->group_next = need_replace_client;
+
+	if (need_replace_client->group_prev) {
+		need_replace_client->group_prev->group_next = need_join_client;
+	}
+
+	need_join_client->group_prev = need_replace_client->group_prev;
+
+	need_replace_client->group_prev = need_join_client;
+
+	client_focus_group_member(need_join_client);
+	arrange(need_join_client->mon, false, false);
+
+	// oldmon可能已经死掉了
+	if (oldmon) {
+		arrange(oldmon, false, false);
 	}
 
 	return 0;
diff --git a/src/mango.c b/src/mango.c
index 90e3ca66..01784257 100644
--- a/src/mango.c
+++ b/src/mango.c
@@ -2761,8 +2761,10 @@ void closemon(Monitor *m) {
 				}
 
 				c->mon = NULL;
+				client_set_group_mon(c, NULL);
 			} else {
 				client_change_mon(c, selmon);
+				client_set_group_mon(c, selmon);
 			}
 			// record the oldmonname which is used to restore
 			if (c->oldmonname[0] == '\0') {