diff --git a/sign/sign.go b/sign/sign.go
index ea37a81..45a86bc 100644
--- a/sign/sign.go
+++ b/sign/sign.go
@@ -51,7 +51,7 @@ type InfoData struct {
 
 type SignDataSignature struct {
 	Approval bool
-	CertType uint32
+	CertType uint
 	Info     SignDataSignatureInfo
 }