diff --git a/gpiozero/input_devices.py b/gpiozero/input_devices.py
index 05682cb..7e89709 100644
--- a/gpiozero/input_devices.py
+++ b/gpiozero/input_devices.py
@@ -534,7 +534,7 @@ class DistanceSensor(SmoothedInputDevice):
         from gpiozero import DistanceSensor
         from time import sleep
 
-        sensor = DistanceSensor(18, 17)
+        sensor = DistanceSensor(echo=18, trigger=17)
         while True:
             print('Distance: ', sensor.distance * 100)
             sleep(1)