diff --git a/src/js/static-filtering-parser.js b/src/js/static-filtering-parser.js
index e36328c3176ca..1be5e41e82454 100644
--- a/src/js/static-filtering-parser.js
+++ b/src/js/static-filtering-parser.js
@@ -3156,6 +3156,7 @@ Parser.utils = Parser.prototype.utils = (( ) => {
 
     const preparserTokens = new Map([
         [ 'ext_ublock', 'ublock' ],
+        [ 'ext_ubol', 'ubol' ],
         [ 'env_chromium', 'chromium' ],
         [ 'env_edge', 'edge' ],
         [ 'env_firefox', 'firefox' ],