diff --git a/com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/util/Util.java b/com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/util/Util.java
index c2fb4f994..8a5a527bd 100644
--- a/com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/util/Util.java
+++ b/com.ibm.wala.cast.js/source/com/ibm/wala/cast/js/util/Util.java
@@ -12,11 +12,20 @@ package com.ibm.wala.cast.js.util;
 
 import java.util.Iterator;
 
+import com.ibm.wala.cast.js.ssa.PrototypeLookup;
 import com.ibm.wala.cast.loader.CAstAbstractLoader;
 import com.ibm.wala.classLoader.IClassLoader;
 import com.ibm.wala.classLoader.ModuleEntry;
 import com.ibm.wala.ipa.cha.IClassHierarchy;
+import com.ibm.wala.ssa.DefUse;
+import com.ibm.wala.ssa.IR;
+import com.ibm.wala.ssa.SSAInstruction;
+import com.ibm.wala.ssa.SSAPhiInstruction;
 import com.ibm.wala.util.WalaException;
+import com.ibm.wala.util.intset.IntSet;
+import com.ibm.wala.util.intset.IntSetAction;
+import com.ibm.wala.util.intset.IntSetUtil;
+import com.ibm.wala.util.intset.MutableIntSet;
 import com.ibm.wala.util.warnings.Warning;
 
 public class Util {
@@ -47,6 +56,49 @@ public class Util {
       throw new WalaException(String.valueOf(message));
     }
   }
+
+  public static IntSet getArgumentsArrayVns(IR ir, final DefUse du) {
+    int originalArgsVn = getArgumentsArrayVn(ir);
+    final MutableIntSet result = IntSetUtil.make();
+    if (originalArgsVn == -1) {
+      return result;
+    }
+    
+    result.add(originalArgsVn);
+    int size; 
+    do {
+      size = result.size();
+      result.foreach(new IntSetAction() {
+        @Override
+        public void act(int vn) {
+          for(Iterator<SSAInstruction> insts = du.getUses(vn); insts.hasNext(); ) {
+            SSAInstruction inst = insts.next();
+            if (inst instanceof PrototypeLookup || inst instanceof SSAPhiInstruction) {
+              result.add(inst.getDef());
+            }
+          }
+        }
+      });
+    } while (size != result.size());
+    
+    return result;
+  }
+  
+  public static int getArgumentsArrayVn(IR ir) {
+    for(int i = 0; i < ir.getInstructions().length; i++) {
+      SSAInstruction inst = ir.getInstructions()[i];
+      if (inst != null) {
+        for(int v = 0; v < inst.getNumberOfUses(); v++) {
+          String[] names = ir.getLocalNames(i, inst.getUse(v));
+          if (names != null && names.length == 1 && "arguments".equals(names[0])) {
+            return inst.getUse(v);
+          }
+        }
+      }
+    }
+    
+    return -1;
+  }
   
 
 }