Index: src/org/openstreetmap/josm/io/GeoJSONExporter.java
===================================================================
--- src/org/openstreetmap/josm/io/GeoJSONExporter.java	(revision 5747)
+++ src/org/openstreetmap/josm/io/GeoJSONExporter.java	(working copy)
@@ -1,9 +1,12 @@
 // License: GPL. For details, see LICENSE file.
 package org.openstreetmap.josm.io;
 
+import java.io.BufferedWriter;
 import java.io.File;
-import java.io.FileWriter;
+import java.io.FileOutputStream;
 import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
 import org.openstreetmap.josm.actions.ExtensionFileFilter;
 import org.openstreetmap.josm.gui.layer.Layer;
 import org.openstreetmap.josm.gui.layer.OsmDataLayer;
@@ -13,7 +16,7 @@
 
     public static final ExtensionFileFilter FILE_FILTER = new ExtensionFileFilter(
             "json,geojson", "json", tr("GeoJSON Files") + " (*.json *.geojson)");
-    
+
     public GeoJSONExporter() {
         super(FILE_FILTER);
     }
@@ -22,7 +25,8 @@
     public void exportData(File file, Layer layer) throws IOException {
         if (layer instanceof OsmDataLayer) {
             String json = new GeoJSONWriter((OsmDataLayer) layer).write();
-            FileWriter out = new FileWriter(file);
+            Writer out = new BufferedWriter(new OutputStreamWriter(
+                new FileOutputStream(file), "UTF-8"));
             out.write(json);
             out.close();
         } else {