diff --git a/project.ant/src/org/netbeans/spi/project/support/ant/ReferenceHelper.java b/project.ant/src/org/netbeans/spi/project/support/ant/ReferenceHelper.java
--- a/project.ant/src/org/netbeans/spi/project/support/ant/ReferenceHelper.java
+++ b/project.ant/src/org/netbeans/spi/project/support/ant/ReferenceHelper.java
@@ -1431,13 +1431,15 @@
             File absolutePath = FileUtil.normalizeFile(PropertyUtils.resolveFile(originalPath, value));
             
 	    if (absolutePath.getAbsolutePath().startsWith(originalPath.getAbsolutePath())) {
-		//#65141: in private.properties, a full path into originalPath may be given, fix:
-		String relative = PropertyUtils.relativizeFile(originalPath, absolutePath);
-		
-		absolutePath = FileUtil.normalizeFile(new File(projectDir, relative));
-		
-		privRemove.add(key);
-		privAdd.put(key, absolutePath.getAbsolutePath());
+            //#65141: in private.properties, a full path into originalPath may be given, fix:
+            String relative = PropertyUtils.relativizeFile(originalPath, absolutePath);
+
+            absolutePath = FileUtil.normalizeFile(new File(projectDir, relative));
+
+            if (priv.containsKey(key)) {
+                privRemove.add(key);
+                privAdd.put(key, absolutePath.getAbsolutePath());
+            }
 	    }
 	    
             //TODO: extra base dir relativization: