diff --git a/pmd/src/net/sourceforge/pmd/cpd/CPDNullListener.java b/pmd/src/net/sourceforge/pmd/cpd/CPDNullListener.java
index 0afe64736f..9a6e98e62f 100644
--- a/pmd/src/net/sourceforge/pmd/cpd/CPDNullListener.java
+++ b/pmd/src/net/sourceforge/pmd/cpd/CPDNullListener.java
@@ -8,9 +8,9 @@ package net.sourceforge.pmd.cpd;
 import java.io.File;
 
 public class CPDNullListener implements CPDListener{
-    public void update(String msg) {}
-    public void addedFile(int fileCount, File file) {}
-    public void addingTokens(int tokenSetCount, int doneSoFar, String tokenSrcID) {}
-    public void addedNewTile(Tile tile, int tilesSoFar, int totalTiles) {}
+    public boolean update(String msg) {return false;}
+    public boolean addedFile(int fileCount, File file) {return false;}
+    public boolean addingTokens(int tokenSetCount, int doneSoFar, String tokenSrcID) {return false;}
+    public boolean addedNewTile(Tile tile, int tilesSoFar, int totalTiles) {return false;}
 		
 }