diff --git a/uk/ac/sanger/artemis/components/EditMenu.java b/uk/ac/sanger/artemis/components/EditMenu.java
index cff413f49eeee627453bdf8a0c547c2616ed2202..63240d63e6d38fe29310bbd7b20cc512bbd835d9 100644
--- a/uk/ac/sanger/artemis/components/EditMenu.java
+++ b/uk/ac/sanger/artemis/components/EditMenu.java
@@ -1725,8 +1725,15 @@ public class EditMenu extends SelectionMenu
             
             try
             {
-              ((Feature)gene1.getGene().getUserData()).addQualifierValues(synQualifier);
-              ((Feature)gene2.getGene().getUserData()).addQualifierValues(synQualifier);
+              Qualifier originalQualifier =
+                  ((Feature)gene1.getGene().getUserData()).getQualifierByName("previous_systematic_id");
+              if( originalQualifier == null ||
+                 !originalQualifier.getValues().contains(prevId+";current=false"))
+              {
+                ((Feature)gene1.getGene().getUserData()).addQualifierValues(synQualifier);
+                ((Feature)gene2.getGene().getUserData()).addQualifierValues(synQualifier);
+              }
+
             }
             catch (Exception e){}
           }