diff --git a/MyTracks/src/com/google/android/apps/mytracks/services/sensors/ZephyrMessageParser.java b/MyTracks/src/com/google/android/apps/mytracks/services/sensors/ZephyrMessageParser.java
index 17c4ae1b3..48fd5daa0 100644
--- a/MyTracks/src/com/google/android/apps/mytracks/services/sensors/ZephyrMessageParser.java
+++ b/MyTracks/src/com/google/android/apps/mytracks/services/sensors/ZephyrMessageParser.java
@@ -40,7 +40,7 @@ public class ZephyrMessageParser implements MessageParser {
     Log.w(Constants.TAG, "Got zephyr data: " + sb);
     // Heart Rate
     Sensor.SensorData.Builder heartrate = Sensor.SensorData.newBuilder()
-        .setValue(buffer[12])
+        .setValue(buffer[12] & 0xFF)
         .setState(Sensor.SensorState.SENDING);
     // Changes Nico Laum (Power and Cadence)
     Sensor.SensorData.Builder power = Sensor.SensorData.newBuilder()