diff --git a/lib/openssl.c b/lib/openssl.c
index fe3d0cc..05f82a2 100644
--- a/lib/openssl.c
+++ b/lib/openssl.c
@@ -1008,7 +1008,7 @@
     ptls_openssl_sign_certificate_t *self = (ptls_openssl_sign_certificate_t *)_self;
     const struct st_ptls_openssl_signature_scheme_t *scheme;
 
-    /* select the algorithm */
+    /* select the algorithm (driven by server-side preference of `self->schemes`) */
     for (scheme = self->schemes; scheme->scheme_id != UINT16_MAX; ++scheme) {
         size_t i;
         for (i = 0; i != num_algorithms; ++i)