diff --git a/boards/sim/sim/sim/configs/rc/defconfig b/boards/sim/sim/sim/configs/rc/defconfig
index 866b2e00ad..b889b727eb 100644
--- a/boards/sim/sim/sim/configs/rc/defconfig
+++ b/boards/sim/sim/sim/configs/rc/defconfig
@@ -45,5 +45,6 @@ CONFIG_SDCLONE_DISABLE=y
 CONFIG_START_MONTH=6
 CONFIG_START_YEAR=2008
 CONFIG_SYSTEM_NSH=y
+CONFIG_TESTING_IRTEST=y
 CONFIG_USERMAIN_STACKSIZE=4096
 CONFIG_USER_ENTRYPOINT="nsh_main"