diff --git a/session/common.go b/session/common.go
index 0eb6254..751a65f 100644
--- a/session/common.go
+++ b/session/common.go
@@ -157,7 +157,6 @@ func (x commonData) signedData(w contextWriter) []byte {
 
 func (x *commonData) sign(key ecdsa.PrivateKey, w contextWriter) error {
 	user.IDFromKey(&x.issuer, key.PublicKey)
-	x.issuerSet = true
 
 	var sig neofscrypto.Signature
 
@@ -166,6 +165,8 @@ func (x *commonData) sign(key ecdsa.PrivateKey, w contextWriter) error {
 		return err
 	}
 
+	x.issuerSet = true
+
 	sig.WriteToV2(&x.sig)
 	x.sigSet = true