diff --git a/uk/ac/sanger/artemis/circular/digest/Utils.java b/uk/ac/sanger/artemis/circular/digest/Utils.java
index 8df7d5918aff17b5750a6c9df3c29761a8b36b9a..06183677b6af646ed1391d5c0c80274427c91549 100644
--- a/uk/ac/sanger/artemis/circular/digest/Utils.java
+++ b/uk/ac/sanger/artemis/circular/digest/Utils.java
@@ -112,6 +112,9 @@ public class Utils
       div = 100000;
     int tickNum = sequenceLength / div;
     int tick = tickNum * (div / 10);
+    
+    if(tick < 1)
+      tick = 2;
     while ((sequenceLength % tick) < (div / 10))
     {
       tickNum++;