Index: trunk/src/org/openstreetmap/josm/actions/mapmode/ImproveWayAccuracyAction.java
===================================================================
--- trunk/src/org/openstreetmap/josm/actions/mapmode/ImproveWayAccuracyAction.java	(revision 10700)
+++ trunk/src/org/openstreetmap/josm/actions/mapmode/ImproveWayAccuracyAction.java	(revision 10701)
@@ -288,4 +288,7 @@
                     p1 = mv.getPoint(nodes.get(index - 1));
                     p2 = mv.getPoint(nodes.get(index + 1));
+                } else if (targetWay.isClosed()) {
+                    p1 = mv.getPoint(targetWay.getNode(1));
+                    p2 = mv.getPoint(targetWay.getNode(nodes.size() - 2));
                 }
                 // TODO: indicate what part that will be deleted? (for end nodes)