diff --git a/src/js/static-filtering-parser.js b/src/js/static-filtering-parser.js
index 844984925..23064335d 100644
--- a/src/js/static-filtering-parser.js
+++ b/src/js/static-filtering-parser.js
@@ -3027,6 +3027,7 @@ Parser.utils = Parser.prototype.utils = (( ) => {
             }
             case 2: /* T_ALTERNATION, 'Alternation' */
             case 8: /* T_CHARGROUP, 'CharacterGroup' */ {
+                if ( node.flags.NegativeMatch ) { return '\x01'; }
                 let firstChar = 0;
                 let lastChar = 0;
                 for ( let i = 0; i < node.val.length; i++ ) {