diff --git a/src/plugins/irc/irc-protocol.c b/src/plugins/irc/irc-protocol.c
index ab4a3dd1e..616f00e44 100644
--- a/src/plugins/irc/irc-protocol.c
+++ b/src/plugins/irc/irc-protocol.c
@@ -3769,12 +3769,16 @@ IRC_PROTOCOL_CALLBACK(301)
  * Callback for the IRC command "303": ison.
  *
  * Command looks like:
- *   :server 303 mynick :nick1 nick2
+ *   303 mynick :nick1 nick2
  */
 
 IRC_PROTOCOL_CALLBACK(303)
 {
-    IRC_PROTOCOL_MIN_ARGS(4);
+    char *str_params;
+
+    IRC_PROTOCOL_MIN_PARAMS(2);
+
+    str_params = irc_protocol_string_params (params, 1, num_params - 1);
 
     weechat_printf_date_tags (
         irc_msgbuffer_get_target_buffer (server, NULL, command, NULL, NULL),
@@ -3783,7 +3787,10 @@ IRC_PROTOCOL_CALLBACK(303)
         _("%sUsers online: %s%s"),
         weechat_prefix ("network"),
         IRC_COLOR_CHAT_NICK,
-        (argv_eol[3][0] == ':') ? argv_eol[3] + 1 : argv_eol[3]);
+        str_params);
+
+    if (str_params)
+        free (str_params);
 
     return WEECHAT_RC_OK;
 }
diff --git a/tests/unit/plugins/irc/test-irc-protocol.cpp b/tests/unit/plugins/irc/test-irc-protocol.cpp
index 951d52e5c..8eeac3df9 100644
--- a/tests/unit/plugins/irc/test-irc-protocol.cpp
+++ b/tests/unit/plugins/irc/test-irc-protocol.cpp
@@ -2288,11 +2288,11 @@ TEST(IrcProtocolWithServer, 303)
 {
     SRV_INIT;
 
-    /* not enough arguments */
+    /* not enough parameters */
     RECV(":server 303");
-    CHECK_ERROR_ARGS("303", 2, 4);
+    CHECK_ERROR_PARAMS("303", 0, 2);
     RECV(":server 303 alice");
-    CHECK_ERROR_ARGS("303", 3, 4);
+    CHECK_ERROR_PARAMS("303", 1, 2);
 
     RECV(":server 303 alice :nick1 nick2");
     CHECK_SRV("-- Users online: nick1 nick2");