diff --git a/src/action.c b/src/action.c
index faa7e73..3e6ac12 100644
--- a/src/action.c
+++ b/src/action.c
@@ -104,3 +104,9 @@ void toggle_client_maximize(const user_action_arg_t *arg) {
 
   client_set_maximize(wm.client_focused, !wm.client_focused->maximize);
 }
+
+void kill_client(const user_action_arg_t *arg) {
+  if (wm.client_focused) {
+    client_kill(wm.client_focused);
+  }
+}
diff --git a/src/action.h b/src/action.h
index d20c367..0273998 100644
--- a/src/action.h
+++ b/src/action.h
@@ -60,3 +60,4 @@ void change_volume(const user_action_arg_t *arg);
 void toggle_client_floating(const user_action_arg_t *arg);
 void toggle_client_fullscreen(const user_action_arg_t *arg);
 void toggle_client_maximize(const user_action_arg_t *arg);
+void kill_client(const user_action_arg_t *arg);
diff --git a/src/atoms-list.txt b/src/atoms-list.txt
index 1875eb9..1fc8d1b 100644
--- a/src/atoms-list.txt
+++ b/src/atoms-list.txt
@@ -1,5 +1,6 @@
 _XKB_RULES_NAMES
 
+WM_DELETE_WINDOW
 WM_PROTOCOLS
 WM_TAKE_FOCUS
 WM_NAME
diff --git a/src/client.c b/src/client.c
index a4125f4..0f92ed0 100644
--- a/src/client.c
+++ b/src/client.c
@@ -172,6 +172,17 @@ static void client_init_tag_by_wm_desktop(client_t *client) {
   }
 }
 
+static void set_window_event_mask(xcb_window_t window, bool clean) {
+  xcb_cw_t change_mask = XCB_CW_EVENT_MASK;
+  uint32_t init_event_mask =
+    XCB_EVENT_MASK_ENTER_WINDOW | XCB_EVENT_MASK_FOCUS_CHANGE |
+    XCB_EVENT_MASK_PROPERTY_CHANGE | XCB_EVENT_MASK_STRUCTURE_NOTIFY |
+    XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY;
+  uint32_t event_mask = clean ? XCB_EVENT_MASK_NO_EVENT : init_event_mask;
+  xcb_params_cw_t params = {.event_mask = event_mask};
+  xcb_aux_change_window_attributes(wm.xcb_conn, window, change_mask, &params);
+}
+
 void client_manage(xcb_window_t window,
                    xcb_get_geometry_reply_t *geometry_reply) {
   client_t *c = p_new(client_t, 1);
@@ -184,14 +195,7 @@ void client_manage(xcb_window_t window,
   c->old_border_width = geometry_reply->border_width;
 
   {
-    const xcb_params_cw_t params = {
-      .event_mask = XCB_EVENT_MASK_ENTER_WINDOW | XCB_EVENT_MASK_FOCUS_CHANGE |
-                    XCB_EVENT_MASK_PROPERTY_CHANGE |
-                    XCB_EVENT_MASK_STRUCTURE_NOTIFY |
-                    XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY,
-    };
-    xcb_aux_change_window_attributes(wm.xcb_conn, window, XCB_CW_EVENT_MASK,
-                                     &params);
+    set_window_event_mask(window, false);
     xcb_map_window(wm.xcb_conn, window);
   }
   client_update_names(c);
@@ -238,6 +242,7 @@ void client_manage(xcb_window_t window,
 
   xcb_change_property(wm.xcb_conn, XCB_PROP_MODE_APPEND, wm.screen->root,
                       _NET_CLIENT_LIST, XCB_ATOM_WINDOW, 32, 1, &window);
+  xwindow_set_state(window, XCB_ICCCM_WM_STATE_NORMAL);
 
   monitor_arrange(c->monitor);
   monitor_draw_bar(c->monitor);
@@ -477,7 +482,13 @@ static void update_client_list(void) {
   }
 }
 
-void client_unmanage(client_t *client) {
+void client_kill(client_t *client) {
+  if (!xwindow_send_event(client->window, WM_DELETE_WINDOW)) {
+    xwindow_kill_window(client->window);
+  }
+}
+
+void client_unmanage(client_t *client, bool destroyed) {
   monitor_t *m = client->monitor;
 
   client_detach_list(client);
@@ -487,6 +498,13 @@ void client_unmanage(client_t *client) {
     if (tag->mask & client->tags) client_remove_from_tag(client, tag);
   }
 
+  if (!destroyed) {
+    set_window_event_mask(client->window, true);
+    client_change_border_width(client, client->old_border_width);
+    xwindow_set_state(client->window, XCB_ICCCM_WM_STATE_WITHDRAWN);
+    xcb_flush(wm.xcb_conn);
+  }
+
   client_wipe(client);
 
   update_client_list();
diff --git a/src/client.h b/src/client.h
index c77a437..19d7c27 100644
--- a/src/client.h
+++ b/src/client.h
@@ -50,7 +50,7 @@ void client_set_transient_for_window(client_t *client,
 void client_set_leader_window(client_t *client, xcb_window_t leader_window);
 
 void client_kill(client_t *client);
-void client_unmanage(client_t *client);
+void client_unmanage(client_t *client, bool destroyed);
 void client_apply_geometry(client_t *client, area_t geometry);
 void client_apply_workarea_geometry(client_t *client, area_t geometry);
 void client_apply_rules(client_t *client, const rule_t rules[],
diff --git a/src/default_config.h b/src/default_config.h
index bc73600..421b195 100644
--- a/src/default_config.h
+++ b/src/default_config.h
@@ -99,6 +99,7 @@ static const keyboard_t key_list[] = {
   {modifier_super | modifier_control, XK_space, toggle_client_floating, {0}},
   {modifier_super, XK_f, toggle_client_fullscreen, {0}},
   {modifier_super, XK_m, toggle_client_maximize, {0}},
+  {modifier_super | modifier_shift, XK_c, kill_client, {0}},
 
   {modifier_super, XK_Up, change_volume, {.i = 1}},
   {modifier_super, XK_Down, change_volume, {.i = -1}},
diff --git a/src/event.c b/src/event.c
index ddba3e0..297aaf7 100644
--- a/src/event.c
+++ b/src/event.c
@@ -4,6 +4,7 @@
 #include <stdint.h>
 #include <xcb/xcb.h>
 #include <xcb/xcb_event.h>
+#include <xcb/xcb_icccm.h>
 #include <xcb/xcb_keysyms.h>
 #include <xcb/xproto.h>
 #include <xkbcommon/xkbcommon.h>
@@ -201,12 +202,18 @@ static void property_notify(xcb_property_notify_event_t *ev) {
 
 static void destroy_notify(xcb_destroy_notify_event_t *ev) {
   client_t *client = client_get_by_window(ev->window);
-  if (client) client_unmanage(client);
+  if (client) client_unmanage(client, true);
 }
 
 static void unmap_notify(xcb_unmap_notify_event_t *ev) {
   client_t *client = client_get_by_window(ev->window);
-  if (client) client_unmanage(client);
+  if (client) {
+    if (XCB_EVENT_SENT(ev)) {
+      xwindow_set_state(ev->window, XCB_ICCCM_WM_STATE_WITHDRAWN);
+    } else {
+      client_unmanage(client, false);
+    }
+  }
 }
 
 static void map_notify(xcb_map_notify_event_t *ev) {
diff --git a/src/wm.c b/src/wm.c
index 8c47380..84ec9b8 100644
--- a/src/wm.c
+++ b/src/wm.c
@@ -314,6 +314,16 @@ void wm_scan_clients(void) {
 void wm_clean(void) {
   clean_status();
   text_clean_pango_layout();
+
+  {
+    client_t *c = wm.client_stack_list;
+    while (c) {
+      client_t *next_client = c->stack_next;
+      client_unmanage(c, false);
+      c = next_client;
+    }
+  }
+
   monitor_clean(wm.monitor_list);
 
   for (int i = 0; i < countof(sources); i++) {
@@ -321,7 +331,6 @@ void wm_clean(void) {
     if (source_id) g_source_remove(source_id);
   }
 
-  xcb_delete_property(wm.xcb_conn, wm.screen->root, _NET_CLIENT_LIST);
   xcb_delete_property(wm.xcb_conn, wm.screen->root, _NET_ACTIVE_WINDOW);
   xcb_delete_property(wm.xcb_conn, wm.screen->root, _NET_SUPPORTING_WM_CHECK);
   xcb_aux_sync(wm.xcb_conn);
diff --git a/src/xwindow.c b/src/xwindow.c
index 607bcc7..ed5b1ca 100644
--- a/src/xwindow.c
+++ b/src/xwindow.c
@@ -228,6 +228,14 @@ bool xwindow_get_wm_desktop(xcb_window_t window, uint32_t *desktop) {
   return success;
 }
 
+void xwindow_kill_window(xcb_window_t window) {
+  xcb_grab_server(wm.xcb_conn);
+  xcb_set_close_down_mode(wm.xcb_conn, XCB_CLOSE_DOWN_DESTROY_ALL);
+  xcb_kill_client(wm.xcb_conn, window);
+  xcb_flush(wm.xcb_conn);
+  xcb_ungrab_server(wm.xcb_conn);
+}
+
 xcb_window_t xwindow_get_transient_for(xcb_window_t window) {
   xcb_connection_t *conn = wm.xcb_conn;
   xcb_window_t t_window = XCB_WINDOW_NONE;
@@ -250,6 +258,23 @@ int32_t xwindow_get_state(xcb_window_t window) {
   return hints.initial_state;
 }
 
+void xwindow_set_state(xcb_window_t window, xcb_icccm_wm_state_t state) {
+  xcb_icccm_wm_hints_t hints;
+  xcb_icccm_wm_hints_set_none(&hints);
+  switch (state) {
+    case XCB_ICCCM_WM_STATE_WITHDRAWN:
+      xcb_icccm_wm_hints_set_withdrawn(&hints);
+      break;
+    case XCB_ICCCM_WM_STATE_NORMAL:
+      xcb_icccm_wm_hints_set_normal(&hints);
+      break;
+    case XCB_ICCCM_WM_STATE_ICONIC:
+      xcb_icccm_wm_hints_set_iconic(&hints);
+      break;
+  }
+  xcb_icccm_set_wm_hints(wm.xcb_conn, window, &hints);
+}
+
 xcb_get_geometry_reply_t *xwindow_get_geometry_reply(xcb_window_t window) {
   xcb_get_geometry_cookie_t cookie = xcb_get_geometry(wm.xcb_conn, window);
   return xcb_get_geometry_reply(wm.xcb_conn, cookie, nullptr);
diff --git a/src/xwindow.h b/src/xwindow.h
index 9f70e41..82a1b7e 100644
--- a/src/xwindow.h
+++ b/src/xwindow.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <xcb/xcb_icccm.h>
 #include <xcb/xproto.h>
 
 #include "action.h"
@@ -22,9 +23,11 @@ void xwindow_get_text_property(xcb_window_t window, xcb_atom_t property,
                                char **out);
 void xwindow_set_wm_desktop(xcb_window_t window, uint32_t desktop);
 bool xwindow_get_wm_desktop(xcb_window_t window, uint32_t *desktop);
+void xwindow_kill_window(xcb_window_t window);
 
 xcb_window_t xwindow_get_transient_for(xcb_window_t window);
 int32_t xwindow_get_state(xcb_window_t window);
+void xwindow_set_state(xcb_window_t window, xcb_icccm_wm_state_t state);
 xcb_get_geometry_reply_t *xwindow_get_geometry_reply(xcb_window_t window);
 xcb_get_window_attributes_reply_t *xwindow_get_attributes_reply(
   xcb_window_t window);