diff --git a/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/DatasetSensorValues.java b/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/DatasetSensorValues.java
index 4ea5935aa..fd5ff50d8 100644
--- a/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/DatasetSensorValues.java
+++ b/WebApp/src/uk/ac/exeter/QuinCe/data/Dataset/DatasetSensorValues.java
@@ -168,9 +168,9 @@ public boolean contains(SensorValue sensorValue) {
   public boolean contains(LocalDateTime time) {
     boolean result = false;
 
-    result = longitudes.containsTime(time);
+    result = null != longitudes && longitudes.containsTime(time);
     if (!result) {
-      result = latitudes.containsTime(time);
+      result = null != latitudes && latitudes.containsTime(time);
     }
     if (!result) {
       for (SensorValuesList sensorValues : valuesByColumn.values()) {