diff --git a/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/SensorValue.java b/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/SensorValue.java
index a3c22c4c5..18c020196 100644
--- a/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/SensorValue.java
+++ b/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/SensorValue.java
@@ -594,7 +594,10 @@ public String getDisplayQCMessage(DatasetSensorValues allSensorValues)
 
       for (SensorValue value : allSensorValues.getById(sourceValues)) {
         if (!(isPosition() && value.isPosition())) {
-          messages.add(value.getDisplayQCMessage(allSensorValues));
+          String qcMessage = value.getDisplayQCMessage(allSensorValues);
+          if (null != qcMessage) {
+            messages.add(qcMessage);
+          }
         }
       }