Index: /trunk/src/org/openstreetmap/josm/data/SystemOfMeasurement.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/data/SystemOfMeasurement.java	(revision 12673)
+++ /trunk/src/org/openstreetmap/josm/data/SystemOfMeasurement.java	(revision 12674)
@@ -13,14 +13,20 @@
 
 import org.openstreetmap.josm.Main;
-import org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference;
+import org.openstreetmap.josm.data.preferences.StringProperty;
 
 /**
  * A system of units used to express length and area measurements.
  * <p>
- * This class also manages one globally set system of measurement stored in the {@link ProjectionPreference}
+ * This class also manages one globally set system of measurement stored in the {@code ProjectionPreference}
  * @since 3406 (creation)
  * @since 6992 (extraction in this package)
  */
 public class SystemOfMeasurement {
+
+    /**
+     * Preferences entry for system of measurement.
+     * @since 12674 (moved from ProjectionPreference)
+     */
+    public static final StringProperty PROP_SYSTEM_OF_MEASUREMENT = new StringProperty("system_of_measurement", "Metric");
 
     /**
@@ -116,5 +122,5 @@
      */
     public static SystemOfMeasurement getSystemOfMeasurement() {
-        return Optional.ofNullable(SystemOfMeasurement.ALL_SYSTEMS.get(ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.get()))
+        return Optional.ofNullable(SystemOfMeasurement.ALL_SYSTEMS.get(PROP_SYSTEM_OF_MEASUREMENT.get()))
                 .orElse(SystemOfMeasurement.METRIC);
     }
@@ -130,6 +136,6 @@
             throw new IllegalArgumentException("Invalid system of measurement: "+somKey);
         }
-        String oldKey = ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.get();
-        if (ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.put(somKey)) {
+        String oldKey = PROP_SYSTEM_OF_MEASUREMENT.get();
+        if (PROP_SYSTEM_OF_MEASUREMENT.put(somKey)) {
             fireSoMChanged(oldKey, somKey);
         }
Index: /trunk/src/org/openstreetmap/josm/gui/MapStatus.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/MapStatus.java	(revision 12673)
+++ /trunk/src/org/openstreetmap/josm/gui/MapStatus.java	(revision 12674)
@@ -71,5 +71,4 @@
 import org.openstreetmap.josm.data.preferences.DoubleProperty;
 import org.openstreetmap.josm.gui.help.Helpful;
-import org.openstreetmap.josm.gui.preferences.projection.ProjectionPreference;
 import org.openstreetmap.josm.gui.progress.PleaseWaitProgressMonitor;
 import org.openstreetmap.josm.gui.progress.PleaseWaitProgressMonitor.ProgressMonitorDialog;
@@ -807,5 +806,5 @@
                     Component invoker = ((JPopupMenu) e.getSource()).getInvoker();
                     jumpButton.setVisible(latText.equals(invoker) || lonText.equals(invoker));
-                    String currentSOM = ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.get();
+                    String currentSOM = SystemOfMeasurement.PROP_SYSTEM_OF_MEASUREMENT.get();
                     for (JMenuItem item : somItems) {
                         item.setSelected(item.getText().equals(currentSOM));
@@ -919,5 +918,5 @@
                 public void mouseClicked(MouseEvent e) {
                     if (!e.isPopupTrigger() && e.getButton() == MouseEvent.BUTTON1) {
-                        String som = ProjectionPreference.PROP_SYSTEM_OF_MEASUREMENT.get();
+                        String som = SystemOfMeasurement.PROP_SYSTEM_OF_MEASUREMENT.get();
                         String newsom = soms.get((soms.indexOf(som)+1) % soms.size());
                         updateSystemOfMeasurement(newsom);
Index: /trunk/src/org/openstreetmap/josm/gui/preferences/projection/ProjectionPreference.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/preferences/projection/ProjectionPreference.java	(revision 12673)
+++ /trunk/src/org/openstreetmap/josm/gui/preferences/projection/ProjectionPreference.java	(revision 12674)
@@ -273,9 +273,8 @@
 
     private static String projectionChoice;
-    
+
     private static final StringProperty PROP_PROJECTION_DEFAULT = new StringProperty("projection.default", mercator.getId());
     private static final StringProperty PROP_COORDINATES = new StringProperty("coordinates", null);
     private static final CollectionProperty PROP_SUB_PROJECTION_DEFAULT = new CollectionProperty("projection.default.sub", null);
-    public static final StringProperty PROP_SYSTEM_OF_MEASUREMENT = new StringProperty("system_of_measurement", "Metric");
     private static final String[] unitsValues = ALL_SYSTEMS.keySet().toArray(new String[ALL_SYSTEMS.size()]);
     private static final String[] unitsValuesTr = new String[unitsValues.length];
@@ -339,5 +338,5 @@
 
         for (int i = 0; i < unitsValues.length; ++i) {
-            if (unitsValues[i].equals(PROP_SYSTEM_OF_MEASUREMENT.get())) {
+            if (unitsValues[i].equals(SystemOfMeasurement.PROP_SYSTEM_OF_MEASUREMENT.get())) {
                 unitsCombo.setSelectedIndex(i);
                 break;