Index: /trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java	(revision 18075)
+++ /trunk/src/org/openstreetmap/josm/data/osm/AbstractPrimitive.java	(revision 18076)
@@ -23,4 +23,5 @@
 import java.util.stream.Stream;
 
+import org.openstreetmap.josm.data.gpx.GpxConstants;
 import org.openstreetmap.josm.spi.preferences.Config;
 import org.openstreetmap.josm.tools.Utils;
@@ -798,5 +799,5 @@
             List<String> l = new LinkedList<>(Arrays.asList(
                 "source", "source_ref", "source:", "comment",
-                "watch", "watch:", "description", "attribution"));
+                "watch", "watch:", "description", "attribution", GpxConstants.GPX_PREFIX));
             l.addAll(getDiscardableKeys());
             l.addAll(getWorkInProgressKeys());
Index: /trunk/src/org/openstreetmap/josm/gui/layer/gpx/ConvertToDataLayerAction.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/layer/gpx/ConvertToDataLayerAction.java	(revision 18075)
+++ /trunk/src/org/openstreetmap/josm/gui/layer/gpx/ConvertToDataLayerAction.java	(revision 18076)
@@ -17,6 +17,4 @@
 
 import org.openstreetmap.josm.actions.SimplifyWayAction;
-import org.openstreetmap.josm.data.gpx.GpxConstants;
-import org.openstreetmap.josm.data.osm.AbstractPrimitive;
 import org.openstreetmap.josm.data.osm.DataSet;
 import org.openstreetmap.josm.data.osm.Way;
@@ -72,11 +70,5 @@
             double err = SimplifyWayAction.askSimplifyWays(ways, tr("Would you like to simplify the ways in the converted layer?"), true);
             if (err > 0) {
-                try {
-                    // Consider the GPX tags uninteresting temporarily, to make sure it doesn't prevent simplification to remove nodes
-                    AbstractPrimitive.getUninterestingKeys().add(GpxConstants.GPX_PREFIX);
-                    SimplifyWayAction.simplifyWays(ways, err);
-                } finally {
-                    AbstractPrimitive.getUninterestingKeys().remove(GpxConstants.GPX_PREFIX);
-                }
+                SimplifyWayAction.simplifyWays(ways, err);
             }
             final OsmDataLayer osmLayer = new OsmDataLayer(ds, tr("Converted from: {0}", layer.getName()), null);