diff --git a/src/prolog/lib/crypto.pl b/src/prolog/lib/crypto.pl
index 0df0dbd7..bf613603 100644
--- a/src/prolog/lib/crypto.pl
+++ b/src/prolog/lib/crypto.pl
@@ -592,7 +592,9 @@ crypto_data_decrypt(CipherText0, Algorithm, Key, IV, PlainText, Options) :-
         must_be_bytes(Key, crypto_data_decrypt/6),
         must_be_bytes(IV, crypto_data_decrypt/6),
         must_be(atom, Algorithm),
-        encoding_options(Encoding, Options),
+        option(encoding(Encoding), Options, utf8),
+        must_be(atom, Encoding),
+        member(Encoding, [utf8,octet]),
         must_be(list, CipherText0),
         encoding_bytes(octet, CipherText0, CipherText1),
         append(CipherText1, Tag, CipherText),