diff --git a/styles/templates/default/tracker.tpl b/styles/templates/default/tracker.tpl
index bf19fecd5..5994dd9ec 100644
--- a/styles/templates/default/tracker.tpl
+++ b/styles/templates/default/tracker.tpl
@@ -508,18 +508,17 @@ $(function(){
 	$('#fs-qs-div').show();
 }
 });
-function get_fs_link ()
-{
-	var fs_url = '{TRACKER_URL}';
-	var fs_val = $('#fs-main').val();
+function get_fs_link() {
+  var fs_url = '{TRACKER_URL}';
+  var fs_val = $('#fs-main').val();
 
-	if (fs_val == null) {
-		alert('{L_NOT_SEL_CHAPTERS}');
-	}
-	else {
-		fs_url += 'f[]='+ fs_val.join('&f[]=');
-		window.prompt('{L_SEL_CHAPTERS}:', fs_url);
-	}
-	return false;
+  if (fs_val != null && $.inArray('-1', fs_val) == -1) {
+    fs_url += 'f=' + fs_val.sort().join();
+    window.prompt('{L_SEL_CHAPTERS}:', fs_url);
+  }
+  else {
+    alert('{L_NOT_SEL_CHAPTERS}');
+  }
+  return false;
 }
 </script>
diff --git a/tracker.php b/tracker.php
index 37ddd8fa3..c4277348b 100644
--- a/tracker.php
+++ b/tracker.php
@@ -375,10 +375,11 @@ if (!$set_default) {
     } // Get requested forum_id(s)
     elseif ($req_forums =& $_REQUEST[$forum_key]) {
         if ($req_forums != $search_all) {
-            $req_forums = (array)$req_forums;
-            array_deep($req_forums, 'intval');
-            $valid_forums = array_intersect($req_forums, $allowed_forums);
-            $forum_val = implode(',', $valid_forums);
+            $clean_forums = [];
+            foreach (explode(',', $req_forums) as $req_forum) {
+                $clean_forums[] = (int) $req_forum;
+            }
+            $forum_val = implode(',', array_intersect($clean_forums, $allowed_forums));
         }
     } elseif (isset($previous_settings[$forum_key])) {
         $valid_forums = array_intersect(explode(',', $previous_settings[$forum_key]), $allowed_forums);