diff --git a/lib/channel.js b/lib/channel.js
index fa0fec9e..a6106119 100644
--- a/lib/channel.js
+++ b/lib/channel.js
@@ -2111,9 +2111,7 @@ Channel.prototype.tryUpdateOptions = function(user, data) {
                 var s = parseFloat(data[key].sustained);
                 if (isNaN(s) || s <= 0)
                     s = 1;
-                var c = parseFloat(data[key].cooldown);
-                if (isNaN(c) || c < 0)
-                    c = 0;
+                var c = b / s;
                 this.opts.chat_antiflood_params.burst = b;
                 this.opts.chat_antiflood_params.sustained = s;
                 this.opts.chat_antiflood_params.cooldown = c;
diff --git a/www/assets/js/channelsettings.js b/www/assets/js/channelsettings.js
index 0492b29b..813ea4b3 100644
--- a/www/assets/js/channelsettings.js
+++ b/www/assets/js/channelsettings.js
@@ -81,8 +81,7 @@
             chat_antiflood: $("#opt_chat_antiflood").prop("checked"),
             chat_antiflood_params: {
                 burst: $("#opt_chat_antiflood_burst").val(),
-                sustained: $("#opt_chat_antiflood_sustained").val(),
-                cooldown: $("#opt_chat_antiflood_cooldown").val()
+                sustained: $("#opt_chat_antiflood_sustained").val()
             },
             show_public: $("#opt_show_public").prop("checked"),
             enable_link_regex: $("#opt_enable_link_regex").prop("checked"),
diff --git a/www/assets/js/util.js b/www/assets/js/util.js
index 0fc13436..266f3985 100644
--- a/www/assets/js/util.js
+++ b/www/assets/js/util.js
@@ -1012,7 +1012,6 @@ function handleModPermissions() {
     $("#opt_chat_antiflood").prop("checked", CHANNEL.opts.chat_antiflood);
     $("#opt_chat_antiflood_burst").val(CHANNEL.opts.chat_antiflood_params.burst);
     $("#opt_chat_antiflood_sustained").val(CHANNEL.opts.chat_antiflood_params.sustained);
-    $("#opt_chat_antiflood_cooldown").val(CHANNEL.opts.chat_antiflood_params.cooldown);
     $("#opt_show_public").prop("checked", CHANNEL.opts.show_public);
     $("#opt_show_public").attr("disabled", CLIENT.rank < 3);
     $("#opt_enable_link_regex").prop("checked", CHANNEL.opts.enable_link_regex);
diff --git a/www/channeloptions.html b/www/channeloptions.html
index a01d456f..4429d535 100644
--- a/www/channeloptions.html
+++ b/www/channeloptions.html
@@ -43,13 +43,6 @@
                 <input type="text" id="opt_chat_antiflood_sustained">
             </div>
         </div>
-        <!-- chat flood cooldown -->
-        <div class="control-group">
-            <label class="control-label" for="opt_chat_antiflood_cooldown" title="The number of seconds since the last message before someone can burst again">Cooldown time after being throttled (seconds)</label>
-            <div class="controls">
-                <input type="text" id="opt_chat_antiflood_cooldown">
-            </div>
-        </div>
         <!-- convert URLs to links -->
         <div class="control-group">
             <label class="control-label" for="opt_enable_link_regex">Convert URLs in chat to links</label>