diff --git a/uk/ac/sanger/artemis/components/genebuilder/gff/PropertiesPanel.java b/uk/ac/sanger/artemis/components/genebuilder/gff/PropertiesPanel.java
index 6d8fed7487d7ea1b62592e5fbf4e0723fd492d97..a02fe756316efafb50093f3b6a467cc59b0eae3d 100644
--- a/uk/ac/sanger/artemis/components/genebuilder/gff/PropertiesPanel.java
+++ b/uk/ac/sanger/artemis/components/genebuilder/gff/PropertiesPanel.java
@@ -162,6 +162,8 @@ public class PropertiesPanel extends JPanel
     if(feature.getEntry().getEntryInformation().isValidQualifier(
        feature.getKey(), "codon_start"))
       addPhaseComponent(c, gridPanel);
+    else
+      phaseButtonGroup = null;
 
     // partial/obsolete options
     if(showOptions)