diff --git a/sim/mcuboot-sys/src/c.rs b/sim/mcuboot-sys/src/c.rs
index 666b038..65ff71f 100644
--- a/sim/mcuboot-sys/src/c.rs
+++ b/sim/mcuboot-sys/src/c.rs
@@ -30,7 +30,7 @@
     let asserts = unsafe { raw::c_asserts };
     unsafe {
         counter.map(|c| *c = raw::flash_counter as i32);
-        api::clear_flash();
+        api::clear_flash(0);
     };
     (result, asserts)
 }