diff --git a/src/js/cosmetic-filtering.js b/src/js/cosmetic-filtering.js
index 4ce2cc01e..9a5d23f28 100644
--- a/src/js/cosmetic-filtering.js
+++ b/src/js/cosmetic-filtering.js
@@ -88,7 +88,7 @@ var FilterPlain = function() {
 };
 
 FilterPlain.prototype.retrieve = function(s, out) {
-    out.push(this.s);
+    out.push(s);
 };
 
 FilterPlain.prototype.fid = '#';