diff --git a/src/html/template/transition.go b/src/html/template/transition.go
index b897bea542..c430389a34 100644
--- a/src/html/template/transition.go
+++ b/src/html/template/transition.go
@@ -414,7 +414,7 @@ func tJSDelimited(c context, s []byte) (context, int) {
// If " 0 && i+7 <= len(s) && bytes.Equal(bytes.ToLower(s[i-1 : i+7]), []byte(" 0 && i+7 <= len(s) && bytes.Equal(bytes.ToLower(s[i-1:i+7]), []byte(" 4) {
+ if len(s) > 4 {
return 0, 0, fmt.Errorf("parseWord(%q): invalid word", s)
}
ret, err := strconv.ParseUint(s, 16, 16)