diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index 78b273a..65e943a 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -435,8 +435,7 @@
 
 uint8_t flash_area_get_device_id(const struct flash_area *fa)
 {
-	(void)fa;
-	return 0;
+    return fa->fa_device_id;
 }
 
 void sim_assert(int x, const char *assertion, const char *file, unsigned int line, const char *function)