diff --git a/sim/mcuboot-sys/csupport/run.c b/sim/mcuboot-sys/csupport/run.c
index 8f2a01c..da2d232 100644
--- a/sim/mcuboot-sys/csupport/run.c
+++ b/sim/mcuboot-sys/csupport/run.c
@@ -397,15 +397,15 @@
 
 int flash_area_id_to_image_slot(int area_id)
 {
-    switch (area_id) {
-    case FLASH_AREA_IMAGE_PRIMARY:
+    if (area_id == FLASH_AREA_IMAGE_PRIMARY) {
         return 0;
-    case FLASH_AREA_IMAGE_SECONDARY:
-        return 1;
-    default:
-        printf("Unsupported image area ID\n");
-        abort();
     }
+    if (area_id == FLASH_AREA_IMAGE_SECONDARY) {
+        return 1;
+    }
+
+    printf("Unsupported image area ID\n");
+    abort();
 }
 
 void sim_assert(int x, const char *assertion, const char *file, unsigned int line, const char *function)