diff --git a/src/compiler/scanner.ts b/src/compiler/scanner.ts
index 343df39ad9cbc..c4e20bb055e28 100644
--- a/src/compiler/scanner.ts
+++ b/src/compiler/scanner.ts
@@ -3915,7 +3915,7 @@ export function createScanner(
 
         if (isIdentifierStart(ch, languageVersion)) {
             let char = ch;
-            while (pos < end && isIdentifierPart(char = codePointUnchecked(pos), languageVersion) || char === CharacterCodes.minus) pos += charSize(char);
+            while (pos < end && (isIdentifierPart(char = codePointUnchecked(pos), languageVersion) || char === CharacterCodes.minus)) pos += charSize(char);
             tokenValue = text.substring(tokenStart, pos);
             if (char === CharacterCodes.backslash) {
                 tokenValue += scanIdentifierParts();