diff --git a/uk/ac/sanger/artemis/circular/digest/CircularGenomeController.java b/uk/ac/sanger/artemis/circular/digest/CircularGenomeController.java
index 1400f9c12f78c9582a4b2d7e8ee8d0ec118f8eed..b472d83eca56fedb521e8808381b1b5571786f06 100644
--- a/uk/ac/sanger/artemis/circular/digest/CircularGenomeController.java
+++ b/uk/ac/sanger/artemis/circular/digest/CircularGenomeController.java
@@ -119,6 +119,9 @@ public class CircularGenomeController
       File sequenceFile = new File(((File) entryGroup.getSequenceEntry()
           .getRootDocument().getLocation()).getAbsolutePath()
           + File.separator + entryGroup.getSequenceEntry().getName());
+      
+      if(sequenceFiles == null)
+        sequenceFiles = new Vector();
       sequenceFiles.add(sequenceFile);
       entries.add(entryGroup);
     }