diff --git a/ChangeLog b/ChangeLog
index bed2ecb7c..3cb164b21 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,7 @@
 WeeChat ChangeLog
 =================
 Sébastien Helleu <flashcode@flashtux.org>
-v0.4.1-dev, 2013-02-04
+v0.4.1-dev, 2013-02-07
 
 
 Version 0.4.1 (under dev!)
@@ -21,6 +21,8 @@ Version 0.4.1 (under dev!)
 * irc: add color in output of /names when result is on server buffer (channel
   not joined) (bug #38070)
 * perl: simplify code to load scripts
+* relay: add options "buffers" and "upgrade" for commands sync/desync in weechat
+  protocol
 * relay: fix commands sync/desync in weechat protocol (bug #38215)
 * scripts: do not allow empty script name in function "register"
 
diff --git a/doc/en/weechat_relay_protocol.en.txt b/doc/en/weechat_relay_protocol.en.txt
index e24f72834..3f8e56a99 100644
--- a/doc/en/weechat_relay_protocol.en.txt
+++ b/doc/en/weechat_relay_protocol.en.txt
@@ -282,43 +282,66 @@ input irc.freenode.#weechat hello guys!
 sync
 ~~~~
 
+_Updated in version 0.4.1._
+
 Synchronize one or more buffers, to get updates.
 
+[IMPORTANT]
+It is recommended to send this command immediately after you asked
+data for buffers (lines, ...). It can be send in same message (after a new
+line).
+
 Syntax:
 
 ----------------------------------------
-sync [<buffer>[,<buffer>...] <options>]
+sync [<buffer>[,<buffer>...] <option>[,<option>...]]
 ----------------------------------------
 
 Arguments:
 
 * 'buffer': pointer ('0x12345') or full name of buffer (for example:
-  'core.weechat' or 'irc.freenode.#weechat'); name '*' can be used to
+  'core.weechat' or 'irc.freenode.#weechat'); name "*" can be used to
   specify all buffers
 * 'options': one of following keywords, separated by commas (default is
-  'buffer,nicklist'):
-** 'buffer': receive signals about buffer (new lines, buffer renamed/moved/...)
+  'buffers,upgrade,buffer,nicklist' for "*" and 'buffer,nicklist' for a buffer):
+** 'buffers': receive signals about buffers (opened/closed, moved, renamed,
+   merged/unmerged, renamed); this can be used only with name "*"
+   (_new in version 0.4.1_)
+** 'upgrade': receive signals about WeeChat upgrade (upgrade, upgrade ended);
+   this can be used only with name "*"
+   (_new in version 0.4.1_)
+** 'buffer': receive signals about buffer (new lines, type changed, title
+    changed, local variable added/removed, and same signals as 'buffers' for the
+    buffer) (_updated in version 0.4.1_)
 ** 'nicklist': receive nicklist after changes
 
 Examples:
 
 ----------------------------------------
-# synchronize all buffers with nicklist (the 3 commands are equivalent)
+# synchronize all buffers with nicklist
+# (the 3 commands are equivalent, but the first one is recommended
+# for compatibility with future versions)
 sync
 sync *
-sync * buffer,nicklist
+sync * buffers,upgrade,buffer,nicklist
 
 # synchronize core buffer
 sync core.buffer
 
 # synchronize #weechat channel, without nicklist
 sync irc.freenode.#weechat buffer
+
+# get general signals + all signals for #weechat channel
+sync * buffers,upgrade
+sync irc.freenode.#weechat
 ----------------------------------------
 
 [[command_desync]]
 desync
 ~~~~~~
 
+_Updated in version 0.4.1._
+
 Desynchronize one or more buffers, to stop updates.
 
 [NOTE]
@@ -328,24 +351,33 @@ buffers, the client will still receive updates for buffers.
 Syntax:
 
 ----------------------------------------
-desync [<buffer>[,<buffer>...] <options>]
+desync [<buffer>[,<buffer>...] <option>[,<option>...]]
 ----------------------------------------
 
 Arguments:
 
 * 'buffer': pointer ('0x12345') or full name of buffer (for example:
-  'core.weechat' or 'irc.freenode.#weechat'); name '*' can be used to
+  'core.weechat' or 'irc.freenode.#weechat'); name "*" can be used to
   specify all buffers
 * 'options': one of following keywords, separated by commas (default is
-  'buffer,nicklist'):
-** 'buffer': receive signals about buffer (new lines, buffer renamed/moved...)
-** 'nicklist': receive nicklist after changes
+  'buffers,upgrade,buffer,nicklist' for "*" and 'buffer,nicklist' for a buffer);
+  see <<command_sync,command sync>> for values.
+
+[NOTE]
+When using buffer "*", the other buffers synchronized (using a name) are kept. +
+So if you send: "sync *", then "sync irc.freenode.#weechat", then "desync *",
+the updates on #weechat channel will still be sent by WeeChat (you must remove
+it explicitly to stop updates).
 
 Examples:
 
 ----------------------------------------
 # desynchronize all buffers
+# (the 3 commands are equivalent, but the first one is recommended
+# for compatibility with future versions)
 desync
+desync *
+desync * buffers,upgrade,buffer,nicklist
 
 # desynchronize nicklist for #weechat channel (keep buffer updates)
 desync irc.freenode.#weechat nicklist
@@ -360,7 +392,12 @@ test
 
 Test command: WeeChat will reply with various different objects.
 
-This command is useful to test the decoding of objects rerutned by WeeChat.
+This command is useful to test the decoding of objects returned by WeeChat.
+
+[IMPORTANT]
+You must not use the pointer values returned by this command, they are not
+valid. This command should only be used to test decoding of a message sent by
+WeeChat.
 
 Syntax:
 
@@ -460,81 +497,81 @@ There are two different identifiers ('id'):
 
 WeeChat reserved identifiers:
 
-[width="100%",cols="5m,5,3,10,8",options="header"]
+[width="100%",cols="5m,5,3,3,10,8",options="header"]
 |=====================================================
-| Identifier               | Description             | Hdata type | Hdata content
+| Identifier | Description | Received with sync | Hdata type | Hdata content
 | Recommended action in client
 
-| _buffer_opened           | Buffer opened           | buffer |
+| _buffer_opened | Buffer opened | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), 'short_name' (string), +
   'nicklist' (integer), 'title' (string), 'local_variables' (hashtable), +
   'prev_buffer' (pointer), 'next_buffer' (pointer) |
   Open buffer
 
-| _buffer_type_changed     | Type of buffer changed  | buffer |
-  'number' (integer), 'full_name' (string), +
-  'type' (integer) |
-  Change type of buffer
-
-| _buffer_moved            | Buffer moved            | buffer |
+| _buffer_moved | Buffer moved | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), +
   'prev_buffer' (pointer), 'next_buffer' (pointer) |
   Move buffer
 
-| _buffer_merged           | Buffer merged           | buffer |
+| _buffer_merged | Buffer merged | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), +
   'prev_buffer' (pointer), 'next_buffer' (pointer) |
   Merge buffer
 
-| _buffer_unmerged         | Buffer unmerged         | buffer |
+| _buffer_unmerged | Buffer unmerged | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), +
   'prev_buffer' (pointer), 'next_buffer' (pointer) |
   Unmerge buffer
 
-| _buffer_renamed          | Buffer renamed          | buffer |
+| _buffer_renamed | Buffer renamed | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), 'short_name' (string),
   'local_variables' (hashtable) |
   Rename buffer
 
-| _buffer_title_changed    | Title of buffer changed | buffer |
+| _buffer_title_changed | Title of buffer changed | buffers / buffer | buffer |
   'number' (integer), 'full_name' (string), 'title' (string) |
   Change title of buffer
 
-| _buffer_localvar_added   | Local variable added    | buffer |
+| _buffer_closing | Buffer closing | buffers / buffer | buffer |
+  'number' (integer), 'full_name' (string) |
+  Close buffer
+
+| _buffer_type_changed | Type of buffer changed | buffer | buffer |
+  'number' (integer), 'full_name' (string), +
+  'type' (integer) |
+  Change type of buffer
+
+| _buffer_localvar_added | Local variable added | buffer | buffer |
   'number' (integer), 'full_name' (string), 'local_variables' (hashtable) |
   Add local variable in buffer
 
-| _buffer_localvar_changed | Local variable changed  | buffer |
+| _buffer_localvar_changed | Local variable changed | buffer | buffer |
   'number' (integer), 'full_name' (string), 'local_variables' (hashtable) |
   Change local variable in buffer
 
-| _buffer_localvar_removed | Local variable removed  | buffer |
+| _buffer_localvar_removed | Local variable removed | buffer | buffer |
   'number' (integer), 'full_name' (string), 'local_variables' (hashtable) |
   Remove local variable from buffer
 
-| _buffer_line_added       | Line added in buffer    | line |
+| _buffer_line_added | Line added in buffer | buffer | line |
   'buffer' (pointer), 'date' (time), 'date_printed' (time), 'displayed' (char),
   'highlight' (char), 'tags_array' (array of strings), 'prefix' (string),
   'message' (string) |
   Display line in buffer
 
-| _buffer_closing          | Buffer closing          | buffer |
-  'number' (integer), 'full_name' (string) |
-  Close buffer
-
-| _nicklist                | Nicklist for a buffer   | nicklist_item |
+| _nicklist | Nicklist for a buffer | nicklist | nicklist_item |
   'group' (char), 'visible' (char), 'level' (integer), +
   'name' (string), 'color' (string), +
   'prefix' (string), 'prefix_color' (string) |
   Update nicklist
 
-| _upgrade                 | WeeChat is upgrading +
-  (_new in version 0.3.8_) | (empty) |
+| _upgrade | WeeChat is upgrading +
+  (_new in version 0.3.8_) | upgrade | (empty) |
   (empty) |
   Desync from WeeChat (send command 'desync')
 
-| _upgrade_ended           | Upgrade of WeeChat done +
-  (_new in version 0.3.8_) | (empty) |
+| _upgrade_ended | Upgrade of WeeChat done +
+  (_new in version 0.3.8_) | upgrade | (empty) |
   (empty) |
   Resync with WeeChat (resend all commands sent on startup after the 'init')
 |=====================================================
diff --git a/src/plugins/relay/weechat/relay-weechat-protocol.c b/src/plugins/relay/weechat/relay-weechat-protocol.c
index 5e3d52e71..489e972bf 100644
--- a/src/plugins/relay/weechat/relay-weechat-protocol.c
+++ b/src/plugins/relay/weechat/relay-weechat-protocol.c
@@ -88,33 +88,59 @@ relay_weechat_protocol_get_buffer (const char *arg)
 }
 
 /*
- * Checks if buffer is synchronized, according to flags.
+ * Gets integer value of a synchronization flag.
+ */
+
+int
+relay_weechat_protocol_sync_flag (const char *flag)
+{
+    if (strcmp (flag, "buffer") == 0)
+        return RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER;
+    if (strcmp (flag, "nicklist") == 0)
+        return RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
+    if (strcmp (flag, "buffers") == 0)
+        return RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS;
+    if (strcmp (flag, "upgrade") == 0)
+        return RELAY_WEECHAT_PROTOCOL_SYNC_UPGRADE;
+
+    /* unknown flag */
+    return 0;
+}
+
+/*
+ * Checks if buffer is synchronized with at least one of the flags given.
  *
- * First search buffer with full_name in hashtable "buffers_sync".
- * If buffer is not found, search "*" (which means "all buffers").
+ * First searches buffer with full_name in hashtable "buffers_sync" (if buffer
+ * is not NULL).
+ * If buffer is NULL or not found, searches "*" (which means "all buffers").
  *
  * The "flags" argument can be a combination (logical OR) of:
  *   RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER
  *   RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST
+ *   RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS
+ *   RELAY_WEECHAT_PROTOCOL_SYNC_UPGRADE
  *
  * Returns:
- *   1: buffer is synchronized for these flags
- *   0: buffer is NOT synchronized for these flags
+ *   1: buffer is synchronized with at least one flag given
+ *   0: buffer is NOT synchronized with any of the flags given
  */
 
 int
-relay_weechat_protocol_buffer_is_sync (struct t_relay_client *ptr_client,
-                                       const char *full_name, int flags)
+relay_weechat_protocol_is_sync (struct t_relay_client *ptr_client,
+                                struct t_gui_buffer *buffer, int flags)
 {
     int *ptr_flags;
 
-    /* search buffer using "full_name" */
-    ptr_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(ptr_client, buffers_sync),
-                                       full_name);
-    if (ptr_flags)
-        return ((*ptr_flags) & flags) ? 1 : 0;
+    /* search buffer using its full name */
+    if (buffer)
+    {
+        ptr_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(ptr_client, buffers_sync),
+                                           weechat_buffer_get_string (buffer, "full_name"));
+        if (ptr_flags)
+            return ((*ptr_flags) & flags) ? 1 : 0;
+    }
 
-    /* search buffer "*" */
+    /* search special name "*" as fallback */
     ptr_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(ptr_client, buffers_sync),
                                        "*");
     if (ptr_flags)
@@ -361,17 +387,23 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,short_name,"
-                                         "nicklist,title,local_variables,"
-                                         "prev_buffer,next_buffer");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,short_name,"
+                                             "nicklist,title,local_variables,"
+                                             "prev_buffer,next_buffer");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strcmp (signal, "buffer_type_changed") == 0)
@@ -380,15 +412,20 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if buffer is synchronized with flag "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,type");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,type");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strcmp (signal, "buffer_moved") == 0)
@@ -397,16 +434,22 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,"
-                                         "prev_buffer,next_buffer");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,"
+                                             "prev_buffer,next_buffer");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if ((strcmp (signal, "buffer_merged") == 0)
@@ -416,16 +459,22 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,"
-                                         "prev_buffer,next_buffer");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,"
+                                             "prev_buffer,next_buffer");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strcmp (signal, "buffer_renamed") == 0)
@@ -434,16 +483,22 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,short_name,"
-                                         "local_variables");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,short_name,"
+                                             "local_variables");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strcmp (signal, "buffer_title_changed") == 0)
@@ -452,15 +507,21 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,title");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,title");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strncmp (signal, "buffer_localvar_", 16) == 0)
@@ -469,15 +530,20 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if buffer is synchronized with flag "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name,local_variables");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name,local_variables");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
     else if (strcmp (signal, "buffer_line_added") == 0)
@@ -503,11 +569,9 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer || (relay_raw_buffer && (ptr_buffer == relay_raw_buffer)))
             return WEECHAT_RC_OK;
 
-        /* check if buffer is synchronized with flag "buffer" */
-        if (relay_weechat_protocol_buffer_is_sync (ptr_client,
-                                                   weechat_buffer_get_string (ptr_buffer,
-                                                                              "full_name"),
-                                                   RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
+        /* send line only if buffer is synchronized with flag "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
             msg = relay_weechat_msg_new (str_signal);
             if (msg)
@@ -530,17 +594,23 @@ relay_weechat_protocol_signal_buffer_cb (void *data, const char *signal,
         if (!ptr_buffer)
             return WEECHAT_RC_OK;
 
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if sync with flag "buffers" or "buffer" */
+        if (relay_weechat_protocol_is_sync (ptr_client, ptr_buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER))
         {
-            snprintf (cmd_hdata, sizeof (cmd_hdata),
-                      "buffer:0x%lx", (long unsigned int)ptr_buffer);
-            weechat_hashtable_remove (RELAY_WEECHAT_DATA(ptr_client, buffers_nicklist),
-                                      cmd_hdata + 7);
-            relay_weechat_msg_add_hdata (msg, cmd_hdata,
-                                         "number,full_name");
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                snprintf (cmd_hdata, sizeof (cmd_hdata),
+                          "buffer:0x%lx", (long unsigned int)ptr_buffer);
+                weechat_hashtable_remove (RELAY_WEECHAT_DATA(ptr_client, buffers_nicklist),
+                                          cmd_hdata + 7);
+                relay_weechat_msg_add_hdata (msg, cmd_hdata,
+                                             "number,full_name");
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
 
@@ -649,14 +719,12 @@ relay_weechat_protocol_signal_nicklist_cb (void *data, const char *signal,
     if (!str_buffer)
         return WEECHAT_RC_OK;
 
-    /* check if buffer is synchronized with flag "nicklist" */
     rc = sscanf (str_buffer, "%lx", &buffer);
     if ((rc != EOF) && (rc != 0))
     {
-        if (relay_weechat_protocol_buffer_is_sync (ptr_client,
-                                                   weechat_buffer_get_string ((void *)buffer,
-                                                                              "full_name"),
-                                                   RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST))
+        /* send nicklist only if buffer is synchronized with flag "nicklist" */
+        if (relay_weechat_protocol_is_sync (ptr_client, (void *)buffer,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST))
         {
             weechat_hashtable_set (RELAY_WEECHAT_DATA(ptr_client, buffers_nicklist),
                                    str_buffer, "1");
@@ -700,11 +768,16 @@ relay_weechat_protocol_signal_upgrade_cb (void *data, const char *signal,
     if ((strcmp (signal, "upgrade") == 0)
         || (strcmp (signal, "upgrade_ended") == 0))
     {
-        msg = relay_weechat_msg_new (str_signal);
-        if (msg)
+        /* send signal only if client is synchronized with flag "upgrade" */
+        if (relay_weechat_protocol_is_sync (ptr_client, NULL,
+                                            RELAY_WEECHAT_PROTOCOL_SYNC_UPGRADE))
         {
-            relay_weechat_msg_send (ptr_client, msg);
-            relay_weechat_msg_free (msg);
+            msg = relay_weechat_msg_new (str_signal);
+            if (msg)
+            {
+                relay_weechat_msg_send (ptr_client, msg);
+                relay_weechat_msg_free (msg);
+            }
         }
     }
 
@@ -723,8 +796,9 @@ relay_weechat_protocol_signal_upgrade_cb (void *data, const char *signal,
 RELAY_WEECHAT_PROTOCOL_CALLBACK(sync)
 {
     char **buffers, **flags, *full_name;
-    int num_buffers, num_flags, i, add_flags, *ptr_old_flags, new_flags;
-    struct t_gui_buffer *ptr_buffer;
+    int num_buffers, num_flags, i, add_flags, mask, *ptr_old_flags, new_flags;
+    int rc;
+    long unsigned int value;
 
     RELAY_WEECHAT_PROTOCOL_MIN_ARGS(0);
 
@@ -732,61 +806,61 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(sync)
                                     &num_buffers);
     if (buffers)
     {
-        add_flags = RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |
-            RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
+        add_flags = RELAY_WEECHAT_PROTOCOL_SYNC_ALL;
         if (argc > 1)
         {
+            add_flags = 0;
             flags = weechat_string_split (argv[1], ",", 0, 0, &num_flags);
             if (flags)
             {
-                add_flags = 0;
                 for (i = 0; i < num_flags; i++)
                 {
-                    if (strcmp (flags[i], "buffer") == 0)
-                        add_flags |= RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER;
-                    else if (strcmp (flags[i], "nicklist") == 0)
-                        add_flags |= RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
-                }
-                if (add_flags == 0)
-                {
-                    add_flags = RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |
-                        RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
+                    add_flags |= relay_weechat_protocol_sync_flag (flags[i]);
                 }
                 weechat_string_free_split (flags);
             }
         }
-        for (i = 0; i < num_buffers; i++)
+        if (add_flags)
         {
-            full_name = NULL;
-            if (strcmp (buffers[i], "*") == 0)
+            for (i = 0; i < num_buffers; i++)
             {
-                full_name = strdup (buffers[i]);
-            }
-            else
-            {
-                ptr_buffer = relay_weechat_protocol_get_buffer (buffers[i]);
-                if (ptr_buffer)
-                    full_name = strdup (weechat_buffer_get_string (ptr_buffer,
-                                                                   "full_name"));
-            }
-            if (full_name)
-            {
-                ptr_old_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                                       full_name);
-                new_flags = ((ptr_old_flags) ? *ptr_old_flags : 0);
-                new_flags |= add_flags;
-                weechat_hashtable_set (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                       full_name,
-                                       &new_flags);
-                free (full_name);
+                full_name = NULL;
+                mask = RELAY_WEECHAT_PROTOCOL_SYNC_FOR_BUFFER;
+                if (strncmp (buffers[i], "0x", 2) == 0)
+                {
+                    rc = sscanf (buffers[i], "%lx", &value);
+                    if ((rc != EOF) && (rc != 0))
+                    {
+                        full_name = strdup (weechat_buffer_get_string ((struct t_gui_buffer *)value,
+                                                                       "full_name"));
+                    }
+                }
+                else
+                {
+                    full_name = strdup (buffers[i]);
+                    if (strcmp (buffers[i], "*") == 0)
+                        mask = RELAY_WEECHAT_PROTOCOL_SYNC_ALL;
+                }
+
+                if (full_name)
+                {
+                    ptr_old_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(client, buffers_sync),
+                                                           full_name);
+                    new_flags = ((ptr_old_flags) ? *ptr_old_flags : 0);
+                    new_flags |= (add_flags & mask);
+                    if (new_flags)
+                    {
+                        weechat_hashtable_set (RELAY_WEECHAT_DATA(client, buffers_sync),
+                                               full_name,
+                                               &new_flags);
+                    }
+                    free (full_name);
+                }
             }
         }
         weechat_string_free_split (buffers);
     }
 
-    if (!RELAY_WEECHAT_DATA(client, hook_signal_buffer))
-        relay_weechat_hook_signals (client);
-
     return WEECHAT_RC_OK;
 }
 
@@ -802,8 +876,9 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(sync)
 RELAY_WEECHAT_PROTOCOL_CALLBACK(desync)
 {
     char **buffers, **flags, *full_name;
-    int num_buffers, num_flags, i, sub_flags, *ptr_old_flags, new_flags;
-    struct t_gui_buffer *ptr_buffer;
+    int num_buffers, num_flags, i, sub_flags, mask, *ptr_old_flags, new_flags;
+    int rc;
+    long unsigned int value;
 
     RELAY_WEECHAT_PROTOCOL_MIN_ARGS(0);
 
@@ -811,74 +886,66 @@ RELAY_WEECHAT_PROTOCOL_CALLBACK(desync)
                                     &num_buffers);
     if (buffers)
     {
-        sub_flags = RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |
-            RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
+        sub_flags = RELAY_WEECHAT_PROTOCOL_SYNC_ALL;
         if (argc > 1)
         {
+            sub_flags = 0;
             flags = weechat_string_split (argv[1], ",", 0, 0, &num_flags);
             if (flags)
             {
-                sub_flags = 0;
                 for (i = 0; i < num_flags; i++)
                 {
-                    if (strcmp (flags[i], "buffer") == 0)
-                        sub_flags |= RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER;
-                    else if (strcmp (flags[i], "nicklist") == 0)
-                        sub_flags |= RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
-                }
-                if (sub_flags == 0)
-                {
-                    sub_flags = RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |
-                        RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST;
+                    sub_flags |= relay_weechat_protocol_sync_flag (flags[i]);
                 }
                 weechat_string_free_split (flags);
             }
         }
-        for (i = 0; i < num_buffers; i++)
+        if (sub_flags)
         {
-            full_name = NULL;
-            if (strcmp (buffers[i], "*") == 0)
+            for (i = 0; i < num_buffers; i++)
             {
-                full_name = strdup (buffers[i]);
-            }
-            else
-            {
-                ptr_buffer = relay_weechat_protocol_get_buffer (buffers[i]);
-                if (ptr_buffer)
+                full_name = NULL;
+                mask = RELAY_WEECHAT_PROTOCOL_SYNC_FOR_BUFFER;
+                if (strncmp (buffers[i], "0x", 2) == 0)
                 {
-                    full_name = strdup (weechat_buffer_get_string (ptr_buffer,
-                                                                   "full_name"));
-                }
-            }
-            if (full_name)
-            {
-                ptr_old_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                                       full_name);
-                new_flags = ((ptr_old_flags) ? *ptr_old_flags : 0);
-                new_flags &= ~sub_flags;
-                if (new_flags)
-                {
-                    weechat_hashtable_set (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                           full_name,
-                                           &new_flags);
+                    rc = sscanf (buffers[i], "%lx", &value);
+                    if ((rc != EOF) && (rc != 0))
+                    {
+                        full_name = strdup (weechat_buffer_get_string ((struct t_gui_buffer *)value,
+                                                                       "full_name"));
+                    }
                 }
                 else
                 {
-                    weechat_hashtable_remove (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                              full_name);
+                    full_name = strdup (buffers[i]);
+                    if (strcmp (buffers[i], "*") == 0)
+                        mask = RELAY_WEECHAT_PROTOCOL_SYNC_ALL;
+                }
+
+                if (full_name)
+                {
+                    ptr_old_flags = weechat_hashtable_get (RELAY_WEECHAT_DATA(client, buffers_sync),
+                                                           full_name);
+                    new_flags = ((ptr_old_flags) ? *ptr_old_flags : 0);
+                    new_flags &= ~(sub_flags & mask);
+                    if (new_flags)
+                    {
+                        weechat_hashtable_set (RELAY_WEECHAT_DATA(client, buffers_sync),
+                                               full_name,
+                                               &new_flags);
+                    }
+                    else
+                    {
+                        weechat_hashtable_remove (RELAY_WEECHAT_DATA(client, buffers_sync),
+                                                  full_name);
+                    }
+                    free (full_name);
                 }
-                free (full_name);
             }
         }
         weechat_string_free_split (buffers);
     }
 
-    if (weechat_hashtable_get_integer (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                       "items_count") == 0)
-    {
-        relay_weechat_unhook_signals (client);
-    }
-
     return WEECHAT_RC_OK;
 }
 
diff --git a/src/plugins/relay/weechat/relay-weechat-protocol.h b/src/plugins/relay/weechat/relay-weechat-protocol.h
index 42427dd60..c4e66d8e3 100644
--- a/src/plugins/relay/weechat/relay-weechat-protocol.h
+++ b/src/plugins/relay/weechat/relay-weechat-protocol.h
@@ -22,6 +22,18 @@
 
 #define RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER   1
 #define RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST 2
+#define RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS  4
+#define RELAY_WEECHAT_PROTOCOL_SYNC_UPGRADE  8
+
+#define RELAY_WEECHAT_PROTOCOL_SYNC_ALL         \
+    (RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |       \
+     RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST |     \
+     RELAY_WEECHAT_PROTOCOL_SYNC_BUFFERS |      \
+     RELAY_WEECHAT_PROTOCOL_SYNC_UPGRADE)
+
+#define RELAY_WEECHAT_PROTOCOL_SYNC_FOR_BUFFER  \
+    (RELAY_WEECHAT_PROTOCOL_SYNC_BUFFER |       \
+     RELAY_WEECHAT_PROTOCOL_SYNC_NICKLIST)
 
 #define RELAY_WEECHAT_PROTOCOL_CALLBACK(__command)                      \
     int                                                                 \
diff --git a/src/plugins/relay/weechat/relay-weechat.c b/src/plugins/relay/weechat/relay-weechat.c
index be729f524..dfb62f06b 100644
--- a/src/plugins/relay/weechat/relay-weechat.c
+++ b/src/plugins/relay/weechat/relay-weechat.c
@@ -219,6 +219,8 @@ relay_weechat_alloc (struct t_relay_client *client)
                                    NULL,
                                    NULL);
         RELAY_WEECHAT_DATA(client, hook_timer_nicklist) = NULL;
+
+        relay_weechat_hook_signals (client);
     }
 }
 
@@ -289,12 +291,7 @@ relay_weechat_alloc_with_infolist (struct t_relay_client *client,
         }
         RELAY_WEECHAT_DATA(client, hook_timer_nicklist) = NULL;
 
-        if (weechat_hashtable_get_integer (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                           "items_count") > 0)
-            relay_weechat_hook_signals (client);
-        if (weechat_hashtable_get_integer (RELAY_WEECHAT_DATA(client, buffers_sync),
-                                           "items_count") > 0)
-            relay_weechat_hook_timer_nicklist (client);
+        relay_weechat_hook_signals (client);
     }
 }