diff --git a/sim/mcuboot-sys/csupport/flash_map.h b/sim/mcuboot-sys/csupport/flash_map.h
index cc02e7e..b27a90c 100644
--- a/sim/mcuboot-sys/csupport/flash_map.h
+++ b/sim/mcuboot-sys/csupport/flash_map.h
@@ -152,7 +152,9 @@
 int flash_area_to_sectors(int idx, int *cnt, struct flash_area *ret);
 
 int flash_area_id_from_image_slot(int slot);
+int flash_area_id_from_multi_image_slot(int image_index, int slot);
 int flash_area_id_to_image_slot(int area_id);
+int flash_area_id_to_multi_image_slot(int image_index, int area_id);
 
 #ifdef __cplusplus
 }
diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index da2d232..32f43c2 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -242,14 +242,12 @@
     return malloc(size);
 }
 
-int flash_area_id_from_image_slot(int slot)
+int flash_area_id_from_multi_image_slot(int image_index, int slot)
 {
-    const int area_id_tab[] = {FLASH_AREA_IMAGE_PRIMARY,
-                               FLASH_AREA_IMAGE_SECONDARY,
-                               FLASH_AREA_IMAGE_SCRATCH};
-
-    if (slot >= 0 && (unsigned)slot < ARRAY_SIZE(area_id_tab)) {
-            return area_id_tab[slot];
+    switch (slot) {
+    case 0: return FLASH_AREA_IMAGE_PRIMARY(image_index);
+    case 1: return FLASH_AREA_IMAGE_SECONDARY(image_index);
+    case 2: return FLASH_AREA_IMAGE_SCRATCH;
     }
 
     printf("Image flash area ID not found\n");
@@ -395,12 +393,12 @@
     return 0;
 }
 
-int flash_area_id_to_image_slot(int area_id)
+int flash_area_id_to_multi_image_slot(int image_index, int area_id)
 {
-    if (area_id == FLASH_AREA_IMAGE_PRIMARY) {
+    if (area_id == FLASH_AREA_IMAGE_PRIMARY(image_index)) {
         return 0;
     }
-    if (area_id == FLASH_AREA_IMAGE_SECONDARY) {
+    if (area_id == FLASH_AREA_IMAGE_SECONDARY(image_index)) {
         return 1;
     }