diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
index 0cec85cc3..d5248f0db 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/Aggregator.java
@@ -34,7 +34,7 @@ public abstract class Aggregator<InputType, OutputType> {
         previous = next;
     }
 
-    protected abstract void computeValue(Raw<InputType> current);
+    protected abstract void computeValue(@NonNull Raw<InputType> current);
 
     /**
      * @return did we process data from a sensor.
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
index 9d4b20a88..c82fa26d0 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorBarometer.java
@@ -1,5 +1,7 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
+import androidx.annotation.NonNull;
+
 import de.dennisguse.opentracks.data.models.AltitudeGainLoss;
 import de.dennisguse.opentracks.data.models.AtmosphericPressure;
 import de.dennisguse.opentracks.sensors.PressureSensorUtils;
@@ -13,7 +15,7 @@ public class AggregatorBarometer extends Aggregator<AtmosphericPressure, Altitud
     }
 
     @Override
-    protected void computeValue(Raw<AtmosphericPressure> current) {
+    protected void computeValue(@NonNull Raw<AtmosphericPressure> current) {
         if (previous == null) {
             lastAcceptedSensorValue = current.value();
             output = new AltitudeGainLoss(0f, 0f);
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
index 7cb7c21fa..c7fce1e6e 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingCadence.java
@@ -2,6 +2,8 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Cadence;
@@ -17,7 +19,7 @@ public class AggregatorCyclingCadence extends Aggregator<CyclingCadenceBluetooth
     }
 
     @Override
-    protected void computeValue(Raw<CyclingCadenceBluetooth.CrankData> current) {
+    protected void computeValue(@NonNull Raw<CyclingCadenceBluetooth.CrankData> current) {
         if (previous == null) {
             return;
         }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
index c3207904f..db7b65d7c 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingDistanceSpeed.java
@@ -2,6 +2,8 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import android.util.Log;
 
+import androidx.annotation.NonNull;
+
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Distance;
@@ -20,7 +22,7 @@ public class AggregatorCyclingDistanceSpeed extends Aggregator<CyclingDistanceSp
     }
 
     @Override
-    protected void computeValue(Raw<CyclingDistanceSpeedBluetooth.WheelData> current) {
+    protected void computeValue(@NonNull Raw<CyclingDistanceSpeedBluetooth.WheelData> current) {
         if (previous == null) {
             return;
         }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
index 69fa67b16..c0aae4df8 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorCyclingPower.java
@@ -1,5 +1,7 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
+import androidx.annotation.NonNull;
+
 import de.dennisguse.opentracks.data.models.Power;
 import de.dennisguse.opentracks.sensors.driver.CyclingPowerBluetooth;
 
@@ -10,7 +12,7 @@ public class AggregatorCyclingPower extends Aggregator<CyclingPowerBluetooth.Dat
     }
 
     @Override
-    public void computeValue(Raw<CyclingPowerBluetooth.Data> current) {
+    public void computeValue(@NonNull Raw<CyclingPowerBluetooth.Data> current) {
         this.output = current.value().power();
     }
 }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
index 669ce2064..c4fe972de 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorGPS.java
@@ -2,6 +2,8 @@ package de.dennisguse.opentracks.sensors.sensorData;
 
 import android.location.Location;
 
+import androidx.annotation.NonNull;
+
 import de.dennisguse.opentracks.data.models.Position;
 
 public class AggregatorGPS extends Aggregator<Location, Position> {
@@ -11,7 +13,7 @@ public class AggregatorGPS extends Aggregator<Location, Position> {
     }
 
     @Override
-    protected void computeValue(Raw<Location> current) {
+    protected void computeValue(@NonNull Raw<Location> current) {
         output = Position.of(current.value(), current.time());
     }
 
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
index b7bc6ad9d..c8d9c71c3 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorHeartRate.java
@@ -1,5 +1,7 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
+import androidx.annotation.NonNull;
+
 import de.dennisguse.opentracks.data.models.HeartRate;
 
 public class AggregatorHeartRate extends Aggregator<HeartRate, HeartRate> {
@@ -9,7 +11,7 @@ public class AggregatorHeartRate extends Aggregator<HeartRate, HeartRate> {
     }
 
     @Override
-    protected void computeValue(Raw<HeartRate> current) {
+    protected void computeValue(@NonNull Raw<HeartRate> current) {
         if (current.value().isValid()) {
             this.output = current.value();
         }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
index a5c7bc34e..033631426 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorRunning.java
@@ -19,7 +19,7 @@ public final class AggregatorRunning extends Aggregator<RunningSpeedAndCadenceBl
     }
 
     @Override
-    public void computeValue(Raw<RunningSpeedAndCadenceBluetooth.Data> current) {
+    public void computeValue(@NonNull Raw<RunningSpeedAndCadenceBluetooth.Data> current) {
         if (previous == null) {
             return;
         }
diff --git a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
index 0355a71ce..5c0e9ead6 100644
--- a/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
+++ b/src/main/java/de/dennisguse/opentracks/sensors/sensorData/AggregatorTemperature.java
@@ -1,5 +1,7 @@
 package de.dennisguse.opentracks.sensors.sensorData;
 
+import androidx.annotation.NonNull;
+
 import java.time.Duration;
 
 import de.dennisguse.opentracks.data.models.Temperature;
@@ -10,7 +12,7 @@ public class AggregatorTemperature extends Aggregator<Temperature, Temperature>
         super(sensorAddress, sensorName);
     }
 
-    protected void computeValue(Raw<Temperature> current) {
+    protected void computeValue(@NonNull Raw<Temperature> current) {
         this.output = current.value();
     }