diff --git a/arch/sim/src/sim/up_idle.c b/arch/sim/src/sim/up_idle.c
index 6de19e9c9e..be6628730f 100644
--- a/arch/sim/src/sim/up_idle.c
+++ b/arch/sim/src/sim/up_idle.c
@@ -23,7 +23,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
-
+#include <debug.h>
 #include <nuttx/arch.h>
 #include <nuttx/power/pm.h>