diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index e1d0c6ced0..e347853818 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1696,7 +1696,7 @@ static int ssl_tls13_parse_server_hello(mbedtls_ssl_context *ssl,
                               cipher_suite, ciphersuite_info->name));
 
 #if defined(MBEDTLS_HAVE_TIME)
-    ssl->session_negotiate->start = time(NULL);
+    ssl->session_negotiate->start = mbedtls_time(NULL);
 #endif /* MBEDTLS_HAVE_TIME */
 
     /* ...
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 33121afa73..dc3c2f070d 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1846,7 +1846,7 @@ static int ssl_tls13_prepare_server_hello(mbedtls_ssl_context *ssl)
                           MBEDTLS_SERVER_HELLO_RANDOM_LEN);
 
 #if defined(MBEDTLS_HAVE_TIME)
-    ssl->session_negotiate->start = time(NULL);
+    ssl->session_negotiate->start = mbedtls_time(NULL);
 #endif /* MBEDTLS_HAVE_TIME */
 
     return ret;