diff --git a/header_test.go b/header_test.go
index 163fdd7b75..af162e59d9 100644
--- a/header_test.go
+++ b/header_test.go
@@ -2335,7 +2335,7 @@ type bufioPeekReader struct {
 }
 
 func (r *bufioPeekReader) Read(b []byte) (int, error) {
-	if r.s == "" {
+	if len(r.s) == 0 {
 		return 0, io.EOF
 	}