diff --git a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
index 5bd3298..c02c30e 100644
--- a/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
+++ b/hyracks/hyracks-storage-am-common/src/main/java/edu/uci/ics/hyracks/storage/am/common/dataflow/IndexDataflowHelper.java
@@ -52,7 +52,7 @@
         this.ioDeviceId = opDesc.getFileSplitProvider().getFileSplits()[partition].getIODeviceId();
         this.file = new FileReference(new File(opDesc.getFileSplitProvider().getFileSplits()[partition].getLocalFile()
                 .getFile().getPath()
-                + "_" + ioDeviceId));
+                + File.separator + "device_id_" + ioDeviceId));
     }
 
     protected abstract IIndex createIndexInstance() throws HyracksDataException;