diff --git a/lib/HTMLParser.js b/lib/HTMLParser.js
index <HASH>..<HASH> 100644
--- a/lib/HTMLParser.js
+++ b/lib/HTMLParser.js
@@ -4205,7 +4205,7 @@ function HTMLParser(address, fragmentContext, options) {
     case 0x0060: // GRAVE ACCENT
       /* falls through */
     default:
-      attrvaluebuf += String.fromCharCode(c);
+      attrvaluebuf += getMatchingChars(UNQUOTEDATTRVAL);
       tokenizer = attribute_value_unquoted_state;
       break;
     }
A small improvement to attribute value parsing performance.

Use `getMatchingChars` when parsing unquoted attribute values.