Index: PropertyUtilsTest.java
===================================================================
--- PropertyUtilsTest.java	(revision 1065498)
+++ PropertyUtilsTest.java	(working copy)
@@ -111,4 +111,39 @@
         assertEquals( "realVersion", interpolated.get( "bar" ) );
         assertEquals( "none filtered", interpolated.get( "none" ) );
     }
+
+    public void testFilterAlreadyKnownProperies()
+        throws Exception
+    {
+        File filterFileA = new File( testDirectory, "filterFileA.properties" );
+        File filterFileB = new File( testDirectory, "filterFileB.properties" );
+
+        if ( filterFileA.exists() )
+        {
+            filterFileA.delete();
+        }
+
+        if ( filterFileB.exists() )
+        {
+            filterFileB.delete();
+        }
+
+        filterFileA.createNewFile();
+        FileWriter writer = new FileWriter( filterFileA );
+
+        writer.write( "untat_na_damgo=gani_man\n" );
+        writer.flush();
+        writer.close();
+
+        filterFileB.createNewFile();
+        writer = new FileWriter( filterFileB );
+
+        writer.write( "key=${untat_na_damgo}\n" );
+        writer.flush();
+        writer.close();
+
+        Properties baseProp = PropertyUtils.loadPropertyFile( filterFileA, false, false );
+        Properties filtered = PropertyUtils.loadPropertyFile( filterFileB, baseProp );
+        assertTrue( filtered.getProperty( "key" ).equals( "gani_man" ) );
+    }
 }