diff --git a/WHATSNEW b/WHATSNEW
index 6b369d21c..03a1022a4 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -17,6 +17,9 @@ Changes that could break older environments:
 Fixed bugs:
 -----------
 
+ * Made VectorSet faster.
+   Bugzilla Report 53622.
+
  * Incorrect URLs in Ant child POMs.
    Bugzilla Report 53617.
 
diff --git a/src/main/org/apache/tools/ant/util/VectorSet.java b/src/main/org/apache/tools/ant/util/VectorSet.java
index 78c0f75d1..3d46da934 100644
--- a/src/main/org/apache/tools/ant/util/VectorSet.java
+++ b/src/main/org/apache/tools/ant/util/VectorSet.java
@@ -21,6 +21,7 @@ import java.util.Collection;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.Set;
 import java.util.Vector;
 
 /**
@@ -191,6 +192,9 @@ public final class VectorSet extends Vector {
     }
 
     public synchronized boolean retainAll(Collection c) {
+        if (!(c instanceof Set)) {
+            c = new HashSet(c);
+        }
         LinkedList l = new LinkedList();
         for (Iterator i = iterator(); i.hasNext(); ) {
             Object o = i.next();