diff --git a/doc/en/weechat_plugin_api.en.adoc b/doc/en/weechat_plugin_api.en.adoc
index 3a15a5cdc..2d0ea9e33 100644
--- a/doc/en/weechat_plugin_api.en.adoc
+++ b/doc/en/weechat_plugin_api.en.adoc
@@ -9017,6 +9017,11 @@ List of signals sent by WeeChat and plugins:
   String: server name. |
   Disconnected from server.
 
+| irc | irc_server_lag_changed +
+  _(WeeChat ≥ 1.8)_ |
+  String: server name. |
+  Lag changed on the server.
+
 | irc | irc_ignore_removing |
   Pointer: ignore. |
   Removing ignore.
diff --git a/doc/fr/weechat_plugin_api.fr.adoc b/doc/fr/weechat_plugin_api.fr.adoc
index 79be5e5ea..5ea932351 100644
--- a/doc/fr/weechat_plugin_api.fr.adoc
+++ b/doc/fr/weechat_plugin_api.fr.adoc
@@ -9198,6 +9198,11 @@ Liste des signaux envoyés par WeeChat et les extensions :
   Chaîne : nom du serveur. |
   Déconnecté du serveur.
 
+| irc | irc_server_lag_changed +
+  _(WeeChat ≥ 1.8)_ |
+  Chaîne : nom du serveur. |
+  Le lag a changé sur le serveur.
+
 | irc | irc_ignore_removing |
   Pointeur : ignore. |
   Suppression d'un ignore en cours.
diff --git a/doc/it/weechat_plugin_api.it.adoc b/doc/it/weechat_plugin_api.it.adoc
index 29caf8d25..deefe144d 100644
--- a/doc/it/weechat_plugin_api.it.adoc
+++ b/doc/it/weechat_plugin_api.it.adoc
@@ -9293,6 +9293,12 @@ List of signals sent by WeeChat and plugins:
   String: nome server. |
   Disconnesso dal server.
 
+// TRANSLATION MISSING
+| irc | irc_server_lag_changed +
+  _(WeeChat ≥ 1.8)_ |
+  String: server name. |
+  Lag changed on the server.
+
 | irc | irc_ignore_removing |
   Puntatore: ignore. |
   Rimozione dell'ignore.
diff --git a/doc/ja/weechat_plugin_api.ja.adoc b/doc/ja/weechat_plugin_api.ja.adoc
index 17860d881..da5fa8ca2 100644
--- a/doc/ja/weechat_plugin_api.ja.adoc
+++ b/doc/ja/weechat_plugin_api.ja.adoc
@@ -9066,6 +9066,12 @@ WeeChat とプラグインが送信するシグナルのリスト:
   String: サーバ名 |
   サーバから切断された
 
+// TRANSLATION MISSING
+| irc | irc_server_lag_changed +
+  _(WeeChat バージョン 1.8 以上で利用可)_ |
+  String: サーバ名 |
+  Lag changed on the server.
+
 | irc | irc_ignore_removing |
   Pointer: 無視 |
   無視条件を削除中
diff --git a/src/plugins/irc/irc-protocol.c b/src/plugins/irc/irc-protocol.c
index 55a3b35a5..67b0109cd 100644
--- a/src/plugins/irc/irc-protocol.c
+++ b/src/plugins/irc/irc-protocol.c
@@ -1838,17 +1838,19 @@ IRC_PROTOCOL_CALLBACK(pong)
         gettimeofday (&tv, NULL);
         server->lag = (int)(weechat_util_timeval_diff (&(server->lag_check_time),
                                                        &tv) / 1000);
-        if (server->lag != server->lag_displayed)
-        {
-            server->lag_displayed = server->lag;
-            weechat_bar_item_update ("lag");
-        }
 
         /* schedule next lag check */
         server->lag_check_time.tv_sec = 0;
         server->lag_check_time.tv_usec = 0;
         server->lag_next_check = time (NULL) +
             weechat_config_integer (irc_config_network_lag_check);
+
+        /* refresh lag bar item if needed */
+        if (server->lag != server->lag_displayed)
+        {
+            server->lag_displayed = server->lag;
+            irc_server_set_lag (server);
+        }
     }
     else
     {
diff --git a/src/plugins/irc/irc-server.c b/src/plugins/irc/irc-server.c
index 2645c6c52..2d6f7eaaf 100644
--- a/src/plugins/irc/irc-server.c
+++ b/src/plugins/irc/irc-server.c
@@ -785,6 +785,34 @@ irc_server_set_prefix_modes_chars (struct t_irc_server *server,
     }
 }
 
+/*
+ * Sets lag in server buffer (local variable), update bar item "lag"
+ * and send signal "irc_server_lag_changed" for the server.
+ */
+
+void
+irc_server_set_lag (struct t_irc_server *server)
+{
+    char str_lag[32];
+
+    if (server->lag >= weechat_config_integer (irc_config_network_lag_min_show))
+    {
+        snprintf (str_lag, sizeof (str_lag),
+                  ((server->lag_check_time.tv_sec == 0) || (server->lag < 1000)) ?
+                  "%.3f" : "%.0f",
+                  ((float)(server->lag)) / 1000);
+        weechat_buffer_set (server->buffer, "localvar_set_lag", str_lag);
+    }
+    else
+    {
+        weechat_buffer_set (server->buffer, "localvar_del_lag", "");
+    }
+    weechat_hook_signal_send ("irc_server_lag_changed",
+                              WEECHAT_HOOK_SIGNAL_STRING,
+                              server->name);
+    weechat_bar_item_update ("lag");
+}
+
 /*
  * Gets prefix_modes for server (for example: "ohv").
  *
@@ -3105,7 +3133,7 @@ irc_server_timer_cb (const void *pointer, void *data, int remaining_calls)
     struct t_irc_redirect *ptr_redirect, *ptr_next_redirect;
     time_t current_time;
     static struct timeval tv;
-    int away_check;
+    int away_check, refresh_lag;
 
     /* make C compiler happy */
     (void) pointer;
@@ -3179,6 +3207,7 @@ irc_server_timer_cb (const void *pointer, void *data, int remaining_calls)
             /* compute lag */
             if (ptr_server->lag_check_time.tv_sec != 0)
             {
+                refresh_lag = 0;
                 gettimeofday (&tv, NULL);
                 ptr_server->lag = (int)(weechat_util_timeval_diff (&(ptr_server->lag_check_time),
                                                                    &tv) / 1000);
@@ -3191,7 +3220,7 @@ irc_server_timer_cb (const void *pointer, void *data, int remaining_calls)
                     if (ptr_server->lag != ptr_server->lag_displayed)
                     {
                         ptr_server->lag_displayed = ptr_server->lag;
-                        weechat_bar_item_update ("lag");
+                        refresh_lag = 1;
                     }
                 }
                 /* lag timeout? => disconnect */
@@ -3219,7 +3248,7 @@ irc_server_timer_cb (const void *pointer, void *data, int remaining_calls)
                         if (ptr_server->lag != ptr_server->lag_displayed)
                         {
                             ptr_server->lag_displayed = ptr_server->lag;
-                            weechat_bar_item_update ("lag");
+                            refresh_lag = 1;
                         }
 
                         /* schedule next lag check in 5 seconds */
@@ -3229,6 +3258,8 @@ irc_server_timer_cb (const void *pointer, void *data, int remaining_calls)
                             weechat_config_integer (irc_config_network_lag_check);
                     }
                 }
+                if (refresh_lag)
+                    irc_server_set_lag (ptr_server);
             }
 
             /* remove redirects if timeout occurs */
@@ -4831,6 +4862,7 @@ irc_server_disconnect (struct t_irc_server *server, int switch_address,
     server->lag_next_check = time (NULL) +
         weechat_config_integer (irc_config_network_lag_check);
     server->lag_last_refresh = 0;
+    irc_server_set_lag (server);
     server->monitor = 0;
     server->monitor_time = 0;
 
diff --git a/src/plugins/irc/irc-server.h b/src/plugins/irc/irc-server.h
index 359c32356..fc7d63e95 100644
--- a/src/plugins/irc/irc-server.h
+++ b/src/plugins/irc/irc-server.h
@@ -289,6 +289,7 @@ extern const char *irc_server_get_isupport_value (struct t_irc_server *server,
                                                   const char *feature);
 extern void irc_server_set_prefix_modes_chars (struct t_irc_server *server,
                                                const char *prefix);
+extern void irc_server_set_lag (struct t_irc_server *server);
 extern const char *irc_server_get_prefix_modes (struct t_irc_server *server);
 extern const char *irc_server_get_prefix_chars (struct t_irc_server *server);
 extern int irc_server_get_prefix_mode_index (struct t_irc_server *server,