diff --git a/adafruit_ble_radio.py b/adafruit_ble_radio.py
index 8d0b56f..ca0702d 100644
--- a/adafruit_ble_radio.py
+++ b/adafruit_ble_radio.py
@@ -147,6 +147,8 @@ def receive(self, timeout=1):
         Returns a message received on the channel on which the radio is
         listening.
 
+        :param float timeout: The length of time (in seconds) the radio listens for a broadcast
+
         :return: A string representation of the received message, or else None.
         """
         msg = self.receive_full(timeout=timeout)