diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index fbcfdb1..b536b66 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -90,9 +90,9 @@
     if( sig_len < rsa_len )
         return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
 
-    if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL,
-                                  MBEDTLS_RSA_PUBLIC, md_alg,
-                                  (unsigned int) hash_len, hash, sig ) ) != 0 )
+    if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, MBEDTLS_RSA_PUBLIC,
+                                          md_alg, (unsigned int) hash_len,
+                                          hash, sig ) ) != 0 )
         return( ret );
 
     /* The buffer contains a valid signature followed by extra data.