diff --git a/library/pkcs5.c b/library/pkcs5.c
index 6cbb520..8d39eab 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -179,7 +179,7 @@
     keylen = mbedtls_cipher_info_get_key_bitlen(cipher_info) / 8;
 
     if (enc_scheme_params.tag != MBEDTLS_ASN1_OCTET_STRING ||
-        enc_scheme_params.len != cipher_info->iv_size) {
+        enc_scheme_params.len != mbedtls_cipher_info_get_iv_size(cipher_info)) {
         return MBEDTLS_ERR_PKCS5_INVALID_FORMAT;
     }