diff --git a/src/sg.c b/src/sg.c
index 22464bc1b..541ef5550 100644
--- a/src/sg.c
+++ b/src/sg.c
@@ -933,7 +933,8 @@ static stlink_backend_t _stlink_sg_backend = {
     _stlink_sg_step,
     _stlink_sg_current_mode,
     _stlink_sg_force_debug,
-    NULL
+    NULL, /* target_voltage */
+    NULL /* set_swdclk */
 };
 
 static stlink_t* stlink_open(const int verbose) {