diff --git a/WHATSNEW b/WHATSNEW
index 86e69357e..685413ea5 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -42,6 +42,8 @@ Fixed bugs:
 
 * <property environment=... /> now works on OS/400.
 
+* <filterset> nested into <filterset>s didn't work.
+
 Other changes:
 --------------
 
diff --git a/docs/manual/CoreTypes/filterset.html b/docs/manual/CoreTypes/filterset.html
index 21bec066f..3611b3dfa 100644
--- a/docs/manual/CoreTypes/filterset.html
+++ b/docs/manual/CoreTypes/filterset.html
@@ -14,9 +14,14 @@ or be read in from a file. FilterSets can appear inside tasks that support this
 feature or at the same level as <CODE>&lt;target&gt;</CODE> - i.e., as
 children of 
 <CODE>&lt;project&gt;</CODE>.</P>
-<P>FilterSets support the <code>id</code> and <code>refid</code> attributes.
-You can define a FilterSet with an <code>id</code> attribute and then refer
-to that definition from another FilterSet with a <code>refid</code> attribute.
+
+<p>FilterSets support the <code>id</code> and <code>refid</code>
+attributes.  You can define a FilterSet with an <code>id</code>
+attribute and then refer to that definition from another FilterSet
+with a <code>refid</code> attribute.  It is also possible to nest
+filtersets into filtersets to get a set union of the contained
+filters.</p>
+
 <p>In addition, FilterSets can specify
 <code>begintoken</code> and/or 
 <code>endtoken</code> attributes to define what to match.</p>
diff --git a/src/etc/testcases/types/filterset.xml b/src/etc/testcases/types/filterset.xml
index 12b272c6b..4fa780af4 100644
--- a/src/etc/testcases/types/filterset.xml
+++ b/src/etc/testcases/types/filterset.xml
@@ -31,6 +31,23 @@
     </copy>
   </target>
   
+  <target name="test-nested-filtersets">
+    <filterset id="1">
+      <filter token="token1" value="value1"/>
+    </filterset>
+    <filterset id="2">
+      <filterset refid="testset.one"/>
+    </filterset>
+    <filterset id="3">
+      <filterset id="4">
+        <filter token="token4" value="value4"/>
+      </filterset>
+    </filterset>
+    <filterset id="5">
+      <filterset refid="1"/>
+    </filterset>
+  </target>
+
   <target name="cleanup">
     <delete file="dest1.txt" quiet="true" />
     <delete file="dest2.txt" quiet="true" />
diff --git a/src/main/org/apache/tools/ant/types/FilterSet.java b/src/main/org/apache/tools/ant/types/FilterSet.java
index c63b21602..6c7789bb4 100644
--- a/src/main/org/apache/tools/ant/types/FilterSet.java
+++ b/src/main/org/apache/tools/ant/types/FilterSet.java
@@ -467,7 +467,7 @@ public class FilterSet extends DataType implements Cloneable {
     *
     * @param filterSet the filterset to be added to this filterset
     */
-    public void addFilterSet(FilterSet filterSet) {
+    public void addConfiguredFilterSet(FilterSet filterSet) {
         if (isReference()) {
             throw noChildrenAllowed();
         }
diff --git a/src/testcases/org/apache/tools/ant/types/FilterSetTest.java b/src/testcases/org/apache/tools/ant/types/FilterSetTest.java
index c31dd182e..316c6fbbd 100644
--- a/src/testcases/org/apache/tools/ant/types/FilterSetTest.java
+++ b/src/testcases/org/apache/tools/ant/types/FilterSetTest.java
@@ -62,6 +62,7 @@ import junit.framework.TestCase;
 import junit.framework.AssertionFailedError;
 
 import java.io.*;
+import java.util.Hashtable;
 
 /**
  * FilterSet testing
@@ -109,7 +110,6 @@ public class FilterSetTest extends BuildFileTest {
      * actually resolve.  
      */
     public void testRecursive() {
-        System.out.println("testRecursive");
         String result = "it works line";
         String line="@test@ line";
         FilterSet fs = new FilterSet();
@@ -126,7 +126,6 @@ public class FilterSetTest extends BuildFileTest {
      * infinite loop.
      */
     public void testInfinite() {
-        System.out.println("testInfinite");
         String result = "@test@ line testvalue";
         String line = "@test@ line @test3@";
         FilterSet fs = new FilterSet();
@@ -139,6 +138,31 @@ public class FilterSetTest extends BuildFileTest {
         assertEquals(result, fs.replaceTokens(line));
     }
 
+    public void testNestedFilterSets() {
+        executeTarget("test-nested-filtersets");
+
+        FilterSet fs = (FilterSet) getProject().getReference("1");
+        Hashtable filters = fs.getFilterHash();
+        assertEquals(1, filters.size());
+        assertEquals("value1", filters.get("token1"));
+
+        fs = (FilterSet) getProject().getReference("2");
+        filters = fs.getFilterHash();
+        assertEquals(2, filters.size());
+        assertEquals("1111", filters.get("aaaa"));
+        assertEquals("2222", filters.get("bbbb"));
+
+        fs = (FilterSet) getProject().getReference("3");
+        filters = fs.getFilterHash();
+        assertEquals(1, filters.size());
+        assertEquals("value4", filters.get("token4"));
+
+        fs = (FilterSet) getProject().getReference("5");
+        filters = fs.getFilterHash();
+        assertEquals(1, filters.size());
+        assertEquals("value1", filters.get("token1"));
+    }
+
     private boolean compareFiles(String name1, String name2) {
         File file1 = new File(name1);
         File file2 = new File(name2);