diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c9cca70..a7c6cac 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -7953,6 +7953,7 @@
         return 0;
     }
 
+    /* Verify callback: precedence order is SSL context, else conf struct. */
     int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *);
     void *p_vrfy;
     if (ssl->f_vrfy != NULL) {