Index: trunk/src/org/openstreetmap/josm/data/projection/CustomProjection.java
===================================================================
--- trunk/src/org/openstreetmap/josm/data/projection/CustomProjection.java	(revision 12292)
+++ trunk/src/org/openstreetmap/josm/data/projection/CustomProjection.java	(revision 12293)
@@ -210,10 +210,21 @@
      * @param pref the string that defines the custom projection
      * @param cacheDir cache directory name
+     * @deprecated unused - remove in 2017-09
      */
     public CustomProjection(String name, String code, String pref, String cacheDir) {
+        this(name, code, pref);
+    }
+
+    /**
+     * Constructs a new {@code CustomProjection} with given name, code and parameters.
+     *
+     * @param name describe projection in one or two words
+     * @param code unique code for this projection - may be null
+     * @param pref the string that defines the custom projection
+     */
+    public CustomProjection(String name, String code, String pref) {
         this.name = name;
         this.code = code;
         this.pref = pref;
-        this.cacheDir = cacheDir;
         try {
             update(pref);
@@ -708,5 +719,5 @@
     /**
      * {@inheritDoc}
-     * @deprecated unused - remove in 2017-07
+     * @deprecated unused - remove in 2017-09
      */
     @Override
Index: trunk/src/org/openstreetmap/josm/gui/preferences/projection/AbstractProjectionChoice.java
===================================================================
--- trunk/src/org/openstreetmap/josm/gui/preferences/projection/AbstractProjectionChoice.java	(revision 12292)
+++ trunk/src/org/openstreetmap/josm/gui/preferences/projection/AbstractProjectionChoice.java	(revision 12293)
@@ -51,4 +51,14 @@
     }
 
+    /**
+    * Get the cache directory name.
+    * @return the cache directory name (base name)
+    * @deprecated unused - remove in 2017-09
+    */
+    @Deprecated
+    public String getCacheDir() {
+        return cacheDir;
+    }
+
     @Override
     public String toString() {
@@ -64,5 +74,5 @@
         String code = getCurrentCode();
         return new CustomProjection(getProjectionName(), code, Optional.ofNullable(Projections.getInit(code))
-                .orElseThrow(() -> new AssertionError("Error: Unknown projection code: " + code)), cacheDir);
+                .orElseThrow(() -> new AssertionError("Error: Unknown projection code: " + code)));
     }
 }