diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 7c2c818d8..ac02e548a 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -705,7 +705,7 @@ static int ssl_save_session_serialize(mbedtls_ssl_context *ssl,
     }
 
     /* get size of the buffer needed */
-    mbedtls_ssl_session_save(&exported_session, NULL, 0, session_data_len);
+    (void) mbedtls_ssl_session_save(&exported_session, NULL, 0, session_data_len);
     *session_data = mbedtls_calloc(1, *session_data_len);
     if (*session_data == NULL) {
         mbedtls_printf(" failed\n  ! alloc %u bytes for session data\n",