diff --git a/html/render.go b/html/render.go
index 4a833b44..d34564f4 100644
--- a/html/render.go
+++ b/html/render.go
@@ -14,7 +14,7 @@ import (
 
 type writer interface {
 	io.Writer
-	WriteByte(c byte) error // in Go 1.1, use io.ByteWriter
+	io.ByteWriter
 	WriteString(string) (int, error)
 }