diff --git a/src/main/java/org/breedinginsight/brapps/importer/services/processors/ExperimentProcessor.java b/src/main/java/org/breedinginsight/brapps/importer/services/processors/ExperimentProcessor.java
index 45d26f7cb..062857af7 100644
--- a/src/main/java/org/breedinginsight/brapps/importer/services/processors/ExperimentProcessor.java
+++ b/src/main/java/org/breedinginsight/brapps/importer/services/processors/ExperimentProcessor.java
@@ -1175,7 +1175,10 @@ private PendingImportObject<BrAPIObservationUnit> fetchOrCreateObsUnitPIO(Progra
     }
 
     boolean isTimestampMatched(String observationHash, String timeStamp) {
-        OffsetDateTime priorStamp = existingObsByObsHash.get(observationHash).getObservationTimeStamp();
+        OffsetDateTime priorStamp = null;
+        if(existingObsByObsHash.get(observationHash)!=null){
+            priorStamp = existingObsByObsHash.get(observationHash).getObservationTimeStamp();
+        }
         if (priorStamp == null) {
             return timeStamp == null;
         }