diff --git a/arch/sim/src/sim/up_hosttime.c b/arch/sim/src/sim/up_hosttime.c
index 03c9ed7d804..549c6874207 100644
--- a/arch/sim/src/sim/up_hosttime.c
+++ b/arch/sim/src/sim/up_hosttime.c
@@ -66,7 +66,7 @@ uint64_t host_gettime(bool rtc)
 
 void host_sleep(uint64_t nsec)
 {
-  usleep(nsec);
+  usleep(nsec / 1000);
 }
 
 /****************************************************************************