diff --git a/ports/nrf/common-hal/pulseio/PulseOut.c b/ports/nrf/common-hal/pulseio/PulseOut.c
index d282043be7..557610bbdf 100644
--- a/ports/nrf/common-hal/pulseio/PulseOut.c
+++ b/ports/nrf/common-hal/pulseio/PulseOut.c
@@ -75,8 +75,8 @@ static void pulseout_event_handler(nrf_timer_event_t event_type, void *p_context
 
     pulse_array_index++;
     // Ignore a zero-length pulse
-    while (pulse_array[pulse_array_index] == 0 &&
-           pulse_array_index < pulse_array_length) {
+    while (pulse_array_index < pulse_array_length &&
+           pulse_array[pulse_array_index] == 0) {
         pulse_array_index++;
     }