diff --git a/gpio_components/input_devices.py b/gpio_components/input_devices.py
index 28295ed..f586d6b 100644
--- a/gpio_components/input_devices.py
+++ b/gpio_components/input_devices.py
@@ -18,6 +18,7 @@ class InputDevice(object):
         self.inactive = 1
         GPIO.setup(pin, GPIO.IN, self.pull)
 
+    @property
     def is_active(self):
         return GPIO.input(self.pin) == self.active