diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 15731ca..3ee157a 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -300,7 +300,7 @@
 
     MBEDTLS_SSL_DEBUG_BUF(3, "verify hash", verify_hash, verify_hash_len);
 
-    if ((ret = mbedtls_pk_verify_new(sig_alg,
+    if ((ret = mbedtls_pk_verify_new((mbedtls_pk_sigalg_t)sig_alg,
                                      &ssl->session_negotiate->peer_cert->pk,
                                      md_alg, verify_hash, verify_hash_len,
                                      p, signature_len)) == 0) {