diff --git a/lib/openssl.c b/lib/openssl.c
index 01ad2a0..90f6984 100644
--- a/lib/openssl.c
+++ b/lib/openssl.c
@@ -1068,7 +1068,7 @@
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }
-        if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, EVP_sha256()) != 1) {
+        if (EVP_PKEY_CTX_set_rsa_mgf1_md(pkey_ctx, scheme->scheme_md()) != 1) {
             ret = PTLS_ERROR_LIBRARY;
             goto Exit;
         }