diff --git a/library/pkcs5.c b/library/pkcs5.c
index e28d5a8..95f44fa 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -96,11 +96,9 @@
     if( ( ret = mbedtls_asn1_get_alg_null( &p, end, &prf_alg_oid ) ) != 0 )
         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT + ret );
 
-    if( MBEDTLS_OID_CMP( MBEDTLS_OID_HMAC_SHA1, &prf_alg_oid ) != 0 )
+    if( mbedtls_oid_get_md_hmac( &prf_alg_oid, md_type ) != 0 )
         return( MBEDTLS_ERR_PKCS5_FEATURE_UNAVAILABLE );
 
-    *md_type = MBEDTLS_MD_SHA1;
-
     if( p != end )
         return( MBEDTLS_ERR_PKCS5_INVALID_FORMAT +
                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );