diff --git a/vendor/golang.org/x/text/unicode/norm/iter.go b/vendor/golang.org/x/text/unicode/norm/iter.go
index ce17f96..417c6b2 100644
--- a/vendor/golang.org/x/text/unicode/norm/iter.go
+++ b/vendor/golang.org/x/text/unicode/norm/iter.go
@@ -128,8 +128,9 @@
 func nextASCIIBytes(i *Iter) []byte {
 	p := i.p + 1
 	if p >= i.rb.nsrc {
+		p0 := i.p
 		i.setDone()
-		return i.rb.src.bytes[i.p:p]
+		return i.rb.src.bytes[p0:p]
 	}
 	if i.rb.src.bytes[p] < utf8.RuneSelf {
 		p0 := i.p