diff --git a/crypto/ecies/ecies.go b/crypto/ecies/ecies.go
index ad856c468c..9f40157012 100644
--- a/crypto/ecies/ecies.go
+++ b/crypto/ecies/ecies.go
@@ -290,7 +290,7 @@ func (prv *PrivateKey) Decrypt(c, s1, s2 []byte) (m []byte, err error) {
 	switch c[0] {
 	case 2, 3, 4:
 		rLen = (prv.PublicKey.Curve.Params().BitSize + 7) / 4
-		if len(c) < (rLen + hLen + 1) {
+		if len(c) < (rLen + hLen + params.BlockSize) {
 			return nil, ErrInvalidMessage
 		}
 	default: