diff --git a/sm2/sm2_dsa_test.go b/sm2/sm2_dsa_test.go
index d57f010..1faa41a 100644
--- a/sm2/sm2_dsa_test.go
+++ b/sm2/sm2_dsa_test.go
@@ -54,8 +54,8 @@ func TestNewPrivateKey(t *testing.T) {
 func TestNewPrivateKeyFromInt(t *testing.T) {
 	// test nil
 	_, err := NewPrivateKeyFromInt(nil)
-	if err == nil || err.Error() != "sm2: invalid private key size" {
-		t.Errorf("should throw sm2: invalid private key size")
+	if err == nil || err.Error() != "sm2: private key is nil" {
+		t.Errorf("should throw sm2: private key is nil")
 	}
 	// test 1
 	_, err = NewPrivateKeyFromInt(big.NewInt(1))
diff --git a/sm2/sm2_keyexchange_sample_test.go b/sm2/sm2_keyexchange_sample_test.go
index a649623..5ccf5f3 100644
--- a/sm2/sm2_keyexchange_sample_test.go
+++ b/sm2/sm2_keyexchange_sample_test.go
@@ -301,7 +301,10 @@ func calculateSampleZA(pub *ecdsa.PublicKey, a *big.Int, uid []byte) ([]byte, er
 	if uidLen > 0 {
 		md.Write(uid)
 	}
-	writeCurveParams(md, pub.Curve.Params())
+	md.Write(bigIntToBytes(pub.Curve, a))
+	md.Write(bigIntToBytes(pub.Curve, pub.Params().B))
+	md.Write(bigIntToBytes(pub.Curve, pub.Params().Gx))
+	md.Write(bigIntToBytes(pub.Curve, pub.Params().Gy))
 	md.Write(bigIntToBytes(pub.Curve, pub.X))
 	md.Write(bigIntToBytes(pub.Curve, pub.Y))
 	return md.Sum(nil), nil