diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 0fb09c4..6e16c07 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1584,7 +1584,12 @@
  */
 static int ssl_tls1_3_process_certificate_verify( mbedtls_ssl_context *ssl )
 {
-    MBEDTLS_SSL_DEBUG_MSG( 1, ( "%s hasn't been implemented", __func__ ) );
+    int ret;
+
+    ret = mbedtls_ssl_tls13_process_certificate_verify( ssl );
+    if( ret != 0 )
+        return( ret );
+
     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
     return( 0 );
 }