diff --git a/ports/raspberrypi/bindings/rp2pio/StateMachine.c b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
index a885a844b9..ae89fcdffb 100644
--- a/ports/raspberrypi/bindings/rp2pio/StateMachine.c
+++ b/ports/raspberrypi/bindings/rp2pio/StateMachine.c
@@ -279,7 +279,7 @@ STATIC mp_obj_t rp2pio_statemachine_make_new(const mp_obj_type_t *type, size_t n
         bufinfo.buf, bufinfo.len / 2,
         args[ARG_frequency].u_int,
         init_bufinfo.buf, init_bufinfo.len / 2,
-        may_exec_bufinfo.buf, bufinfo.len / 2,
+        may_exec_bufinfo.buf, may_exec_bufinfo.len / 2,
         first_out_pin, out_pin_count, args[ARG_initial_out_pin_state].u_int, args[ARG_initial_out_pin_direction].u_int,
         first_in_pin, in_pin_count, args[ARG_pull_in_pin_up].u_int, args[ARG_pull_in_pin_down].u_int,
         first_set_pin, set_pin_count, args[ARG_initial_set_pin_state].u_int, args[ARG_initial_set_pin_direction].u_int,