diff --git a/ports/raspberrypi/common-hal/rp2pio/StateMachine.c b/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
index bee77238b5..9e8d5feebc 100644
--- a/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
+++ b/ports/raspberrypi/common-hal/rp2pio/StateMachine.c
@@ -436,7 +436,7 @@ void common_hal_rp2pio_statemachine_construct(rp2pio_statemachine_obj_t *self,
                 if (first_in_pin == NULL) {
                     mp_raise_ValueError_varg(translate("Missing first_in_pin. Instruction %d waits based on pin"), i);
                 }
-                if (wait_index > in_pin_count) {
+                if (wait_index >= in_pin_count) {
                     mp_raise_ValueError_varg(translate("Instruction %d waits on input outside of count"), i);
                 }
             }