diff --git a/ChangeLog.asciidoc b/ChangeLog.asciidoc
index 282547d59..e87b1e061 100644
--- a/ChangeLog.asciidoc
+++ b/ChangeLog.asciidoc
@@ -37,6 +37,7 @@ https://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 * api: add support of full color option name in functions color() and
   string_eval_expression() and in command /eval
 * api: add "_chat_line" (line pointer) in hashtable of hook_focus
+* irc: optimize search of a nick in nicklist (up to 3x faster)
 * irc: add support of SHA-256 and SHA-512 algorithms in server option
   "ssl_fingerprint" (closes #281)
 * irc: add option "-noswitch" in command /query (closes #394)
diff --git a/src/plugins/irc/irc-buffer.c b/src/plugins/irc/irc-buffer.c
index c7daa2c23..41491f10e 100644
--- a/src/plugins/irc/irc-buffer.c
+++ b/src/plugins/irc/irc-buffer.c
@@ -180,12 +180,22 @@ irc_buffer_nickcmp_cb (void *data,
                        const char *nick1,
                        const char *nick2)
 {
-    IRC_BUFFER_GET_SERVER(buffer);
+    struct t_irc_server *server;
 
-    /* make C compiler happy */
-    (void) data;
+    if (data)
+        server = (struct t_irc_server *)data;
+    else
+        irc_buffer_get_server_and_channel (buffer, &server, NULL);
 
-    return irc_server_strcasecmp (ptr_server, nick1, nick2);
+    if (server)
+    {
+        return irc_server_strcasecmp (server, nick1, nick2);
+    }
+    else
+    {
+        /* default is RFC 1459 casemapping comparison */
+        return weechat_strcasecmp_range (nick1, nick2, 29);
+    }
 }
 
 /*
diff --git a/src/plugins/irc/irc-channel.c b/src/plugins/irc/irc-channel.c
index 74bc9ba39..1a6bc7226 100644
--- a/src/plugins/irc/irc-channel.c
+++ b/src/plugins/irc/irc-channel.c
@@ -351,6 +351,8 @@ irc_channel_create_buffer (struct t_irc_server *server,
             weechat_buffer_set (ptr_buffer, "nicklist_display_groups", "0");
             weechat_buffer_set_pointer (ptr_buffer, "nickcmp_callback",
                                         &irc_buffer_nickcmp_cb);
+            weechat_buffer_set_pointer (ptr_buffer, "nickcmp_callback_data",
+                                        server);
         }
 
         /* set highlights settings on channel buffer */
diff --git a/src/plugins/irc/irc-upgrade.c b/src/plugins/irc/irc-upgrade.c
index 95b464f69..d62147520 100644
--- a/src/plugins/irc/irc-upgrade.c
+++ b/src/plugins/irc/irc-upgrade.c
@@ -245,6 +245,7 @@ irc_upgrade_set_buffer_callbacks ()
 {
     struct t_infolist *infolist;
     struct t_gui_buffer *ptr_buffer;
+    struct t_irc_server *ptr_server;
     const char *type;
 
     infolist = weechat_infolist_get ("buffer", NULL, NULL);
@@ -260,8 +261,17 @@ irc_upgrade_set_buffer_callbacks ()
                 type = weechat_buffer_get_string (ptr_buffer, "localvar_type");
                 if (type && (strcmp (type, "channel") == 0))
                 {
+                    ptr_server = irc_server_search (
+                        weechat_buffer_get_string (ptr_buffer,
+                                                   "localvar_server"));
                     weechat_buffer_set_pointer (ptr_buffer, "nickcmp_callback",
                                                 &irc_buffer_nickcmp_cb);
+                    if (ptr_server)
+                    {
+                        weechat_buffer_set_pointer (ptr_buffer,
+                                                    "nickcmp_callback_data",
+                                                    ptr_server);
+                    }
                 }
                 if (strcmp (weechat_infolist_string (infolist, "name"),
                             IRC_RAW_BUFFER_NAME) == 0)