diff --git a/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java b/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
index 163e476..64c4ea3 100644
--- a/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
+++ b/pregelix-core/src/main/java/edu/uci/ics/pregelix/core/jobgen/JobGen.java
@@ -507,7 +507,8 @@
         if (BspUtils.useLSM(conf)) {
             return new LSMBTreeDataflowHelperFactory(new VirtualBufferCacheProvider(),
                     new ConstantMergePolicyFactory(), MERGE_POLICY_PROPERTIES, NoOpOperationTrackerProvider.INSTANCE,
-                    SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE, 0.01);
+                    /* TODO verify whether key dup check is required or not in preglix: to be safe, just check it as it has been done*/
+                    SynchronousSchedulerProvider.INSTANCE, NoOpIOOperationCallback.INSTANCE, 0.01, true);
         } else {
             return new BTreeDataflowHelperFactory();
         }
@@ -889,7 +890,7 @@
     public void setLocationConstraint(JobSpecification spec, IOperatorDescriptor operator) {
         optimizer.setOptimizedLocationConstraints(spec, operator);
     }
-    
+
     /**
      * get the file split provider
      * 
@@ -897,7 +898,7 @@
      * @param indexName
      * @return the IFileSplitProvider instance
      */
-    public IFileSplitProvider getFileSplitProvider(String jobId, String indexName){
+    public IFileSplitProvider getFileSplitProvider(String jobId, String indexName) {
         return optimizer.getOptimizedFileSplitProvider(jobId, indexName);
     }