Index: /trunk/src/org/openstreetmap/josm/io/session/ImagerySessionExporter.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/io/session/ImagerySessionExporter.java	(revision 9000)
+++ /trunk/src/org/openstreetmap/josm/io/session/ImagerySessionExporter.java	(revision 9001)
@@ -22,4 +22,5 @@
 import org.openstreetmap.josm.gui.layer.TMSLayer;
 import org.openstreetmap.josm.gui.layer.WMSLayer;
+import org.openstreetmap.josm.gui.layer.WMTSLayer;
 import org.openstreetmap.josm.io.session.SessionWriter.ExportSupport;
 import org.openstreetmap.josm.tools.GBC;
@@ -43,4 +44,8 @@
 
     public ImagerySessionExporter(WMSLayer layer) {
+        this((ImageryLayer) layer);
+    }
+
+    public ImagerySessionExporter(WMTSLayer layer) {
         this((ImageryLayer) layer);
     }