diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 17b1ccf93..08f993466 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -1482,7 +1482,7 @@ int main( int argc, char *argv[] )
         p = (char *) opt.sig_algs;
         i = 0;
 
-        /* Leave room for a final NULL in signature algorithm list */
+        /* Leave room for a final MBEDTLS_TLS13_SIG_NONE in signature algorithm list(sig_alg_list) */
         while( i < SIG_ALG_LIST_SIZE - 1 && *p != '\0' )
         {
             q = p;
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index c7110e850..d5ec6a7cd 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -2205,7 +2205,7 @@ int main( int argc, char *argv[] )
         p = (char *) opt.sig_algs;
         i = 0;
 
-        /* Leave room for a final NULL in signature algorithm list */
+        /* Leave room for a final MBEDTLS_TLS13_SIG_NONE in signature algorithm list(sig_alg_list) */
         while( i < SIG_ALG_LIST_SIZE - 1 && *p != '\0' )
         {
             q = p;