diff --git a/reader.go b/reader.go
index c8155bb..1f9dbba 100644
--- a/reader.go
+++ b/reader.go
@@ -117,7 +117,11 @@ func (d *decoder) decodeHeader() error {
 
 	comment := false
 	for fields := 0; fields < 3; {
-		b, _ = d.br.ReadByte()
+		b, err = d.br.ReadByte()
+		if err != nil {
+			return errBadHeader
+		}
+
 		if b == '#' {
 			comment = true
 		} else if !comment {