diff --git a/demos/STM32/RT-STM32F407-DISCOVERY/main.c b/demos/STM32/RT-STM32F407-DISCOVERY/main.c
index 34e504aeb..e6930f4e8 100644
--- a/demos/STM32/RT-STM32F407-DISCOVERY/main.c
+++ b/demos/STM32/RT-STM32F407-DISCOVERY/main.c
@@ -70,5 +70,6 @@ int main(void) {
   while (TRUE) {
     if (palReadPad(GPIOA, GPIOA_BUTTON))
       TestThread(&SD2);
+    chThdSleepMilliseconds(500);
   }
 }