diff --git a/src/plugins/irc/irc-buffer.c b/src/plugins/irc/irc-buffer.c
index 37d731a35..0ee0b8932 100644
--- a/src/plugins/irc/irc-buffer.c
+++ b/src/plugins/irc/irc-buffer.c
@@ -160,6 +160,29 @@ irc_buffer_close_cb (void *data, struct t_gui_buffer *buffer)
     return WEECHAT_RC_OK;
 }
 
+/*
+ * irc_buffer_nickcmp_cb: callback for comparing nick in nicklist
+ *                        (called when searching a nick in nicklist)
+ *                        Return (according to casemapping of irc server):
+ *                           0 if nick1 == nick2
+ *                          -1 if nick1 < nick2
+ *                          +1 if nick1 > nick2
+ */
+
+int
+irc_buffer_nickcmp_cb (void *data,
+                       struct t_gui_buffer *buffer,
+                       const char *nick1,
+                       const char *nick2)
+{
+    IRC_BUFFER_GET_SERVER(buffer);
+
+    /* make C compiler happy */
+    (void) data;
+
+    return irc_server_strcasecmp (ptr_server, nick1, nick2);
+}
+
 /*
  * irc_buffer_search_first_for_all_servers: search first server buffer that
  *                                          will be used to merge all IRC
diff --git a/src/plugins/irc/irc-buffer.h b/src/plugins/irc/irc-buffer.h
index e7c6259bc..20aefcd80 100644
--- a/src/plugins/irc/irc-buffer.h
+++ b/src/plugins/irc/irc-buffer.h
@@ -53,6 +53,10 @@ extern void irc_buffer_get_server_and_channel (struct t_gui_buffer *buffer,
                                                struct t_irc_channel **channel);
 extern char *irc_buffer_build_name (const char *server, const char *channel);
 extern int irc_buffer_close_cb (void *data, struct t_gui_buffer *buffer);
+extern int irc_buffer_nickcmp_cb (void *data,
+                                  struct t_gui_buffer *buffer,
+                                  const char *nick1,
+                                  const char *nick2);
 extern struct t_gui_buffer *irc_buffer_search_first_for_all_servers ();
 
 #endif /* __WEECHAT_IRC_BUFFER_H */
diff --git a/src/plugins/irc/irc-channel.c b/src/plugins/irc/irc-channel.c
index 626cd531c..ce2e33d5d 100644
--- a/src/plugins/irc/irc-channel.c
+++ b/src/plugins/irc/irc-channel.c
@@ -226,6 +226,8 @@ irc_channel_new (struct t_irc_server *server, int channel_type,
         {
             weechat_buffer_set (new_buffer, "nicklist", "1");
             weechat_buffer_set (new_buffer, "nicklist_display_groups", "0");
+            weechat_buffer_set_pointer (new_buffer, "nickcmp_callback",
+                                        &irc_buffer_nickcmp_cb);
         }
 
         /* set highlights settings on channel buffer */
diff --git a/src/plugins/irc/irc-upgrade.c b/src/plugins/irc/irc-upgrade.c
index a13da06b4..6af4f8b2b 100644
--- a/src/plugins/irc/irc-upgrade.c
+++ b/src/plugins/irc/irc-upgrade.c
@@ -240,6 +240,7 @@ irc_upgrade_set_buffer_callbacks ()
 {
     struct t_infolist *infolist;
     struct t_gui_buffer *ptr_buffer;
+    const char *type;
 
     infolist = weechat_infolist_get ("buffer", NULL, NULL);
     if (infolist)
@@ -251,6 +252,12 @@ irc_upgrade_set_buffer_callbacks ()
                 ptr_buffer = weechat_infolist_pointer (infolist, "pointer");
                 weechat_buffer_set_pointer (ptr_buffer, "close_callback", &irc_buffer_close_cb);
                 weechat_buffer_set_pointer (ptr_buffer, "input_callback", &irc_input_data_cb);
+                type = weechat_buffer_get_string (ptr_buffer, "localvar_type");
+                if (type && (strcmp (type, "channel") == 0))
+                {
+                    weechat_buffer_set_pointer (ptr_buffer, "nickcmp_callback",
+                                                &irc_buffer_nickcmp_cb);
+                }
                 if (strcmp (weechat_infolist_string (infolist, "name"),
                             IRC_RAW_BUFFER_NAME) == 0)
                 {