diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/callGraph/CallGraphTest.java b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/callGraph/CallGraphTest.java
index 60da43bbc..d60040a3d 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/callGraph/CallGraphTest.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/callGraph/CallGraphTest.java
@@ -257,7 +257,7 @@ public class CallGraphTest extends WalaTestCase {
     PointerAnalysis pa = builder.getPointerAnalysis();
     CGNode mainMethod = AbstractPtrTest.findMainMethod(cg);
     PointerKey keyToQuery = AbstractPtrTest.getParam(mainMethod, "testThisVar", pa.getHeapModel());
-    OrdinalSet<InstanceKey> pointsToSet = pa.getPointsToSet(keyToQuery);
+    OrdinalSet<? extends InstanceKey> pointsToSet = pa.getPointsToSet(keyToQuery);
     Assert.assertEquals(1, pointsToSet.size());
     
   }
diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/MultiDimArrayTest.java b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/MultiDimArrayTest.java
index 86cdfeee2..3dd6b3641 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/MultiDimArrayTest.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/MultiDimArrayTest.java
@@ -70,7 +70,7 @@ public class MultiDimArrayTest extends WalaTestCase {
     
     CGNode node = findDoNothingNode(cg);
     PointerKey pk = pa.getHeapModel().getPointerKeyForLocal(node, 1);
-    OrdinalSet<InstanceKey> ptsTo = pa.getPointsToSet(pk);
+    OrdinalSet<? extends InstanceKey> ptsTo = pa.getPointsToSet(pk);
     Assert.assertEquals(1, ptsTo.size());
   }
   
diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/TypeBasedArrayAliasTest.java b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/TypeBasedArrayAliasTest.java
index 29c3ff88b..6360d7856 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/TypeBasedArrayAliasTest.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/TypeBasedArrayAliasTest.java
@@ -78,8 +78,8 @@ public class TypeBasedArrayAliasTest extends WalaTestCase {
   }
 
   private static boolean mayAliased(PointerKey pk1, PointerKey pk2, PointerAnalysis pa) {
-    OrdinalSet<InstanceKey> ptsTo1 = pa.getPointsToSet(pk1);
-    OrdinalSet<InstanceKey> ptsTo2 = pa.getPointsToSet(pk2);
+    OrdinalSet<? extends InstanceKey> ptsTo1 = pa.getPointsToSet(pk1);
+    OrdinalSet<? extends InstanceKey> ptsTo2 = pa.getPointsToSet(pk2);
     boolean foundIntersection = false;
     outer: for (InstanceKey i : ptsTo1) {
       for (InstanceKey j : ptsTo2) {
diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/ZeroLengthArrayTest.java b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/ZeroLengthArrayTest.java
index 3070c0d8d..22ad2b832 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/ZeroLengthArrayTest.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/core/tests/ptrs/ZeroLengthArrayTest.java
@@ -60,10 +60,10 @@ public class ZeroLengthArrayTest {
         cha.resolveMethod(MethodReference.findOrCreate(
             TypeReference.findOrCreate(ClassLoaderReference.Application, TestConstants.ZERO_LENGTH_ARRAY_MAIN),
             Selector.make("main([Ljava/lang/String;)V"))), Everywhere.EVERYWHERE);
-    OrdinalSet<InstanceKey> pointsToSet = pa.getPointsToSet(heapModel.getPointerKeyForLocal(mainNode, 4));
+    OrdinalSet<? extends InstanceKey> pointsToSet = pa.getPointsToSet(heapModel.getPointerKeyForLocal(mainNode, 4));
     Assert.assertEquals(1, pointsToSet.size());
     InstanceKey arrayKey = pointsToSet.iterator().next();
-    OrdinalSet<InstanceKey> arrayContents = pa.getPointsToSet(heapModel.getPointerKeyForArrayContents(arrayKey));
+    OrdinalSet<? extends InstanceKey> arrayContents = pa.getPointsToSet(heapModel.getPointerKeyForArrayContents(arrayKey));
     System.err.println(arrayContents);
     Assert.assertEquals(0, arrayContents.size());
     
diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/demandpa/driver/CompareToZeroOneCFADriver.java b/com.ibm.wala.core.tests/src/com/ibm/wala/demandpa/driver/CompareToZeroOneCFADriver.java
index efc6a0113..bd05eaa25 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/demandpa/driver/CompareToZeroOneCFADriver.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/demandpa/driver/CompareToZeroOneCFADriver.java
@@ -174,7 +174,7 @@ public class CompareToZeroOneCFADriver {
             LocalPointerKey pk = (LocalPointerKey) heapModel.getPointerKeyForLocal(node, i);
             LocalPointerKey oldPk = (LocalPointerKey) CallGraphMapUtil.mapPointerKey(pk, cg, oldCG, heapModel);
             Collection<InstanceKey> p2set = dmp.getPointsTo(pk);
-            OrdinalSet<InstanceKey> otherP2Set = pa.getPointsToSet(oldPk);
+            OrdinalSet<? extends InstanceKey> otherP2Set = pa.getPointsToSet(oldPk);
             System.err.println(("OLD POINTS-TO " + otherP2Set));
             for (InstanceKey key : otherP2Set) {
               if (knownBug(key)) {
diff --git a/com.ibm.wala.core.tests/src/com/ibm/wala/examples/analysis/SimpleThreadEscapeAnalysis.java b/com.ibm.wala.core.tests/src/com/ibm/wala/examples/analysis/SimpleThreadEscapeAnalysis.java
index d72f4b077..2cbaf3d6d 100644
--- a/com.ibm.wala.core.tests/src/com/ibm/wala/examples/analysis/SimpleThreadEscapeAnalysis.java
+++ b/com.ibm.wala.core.tests/src/com/ibm/wala/examples/analysis/SimpleThreadEscapeAnalysis.java
@@ -256,8 +256,8 @@ public class SimpleThreadEscapeAnalysis extends AbstractAnalysisEngine {
     //
     for (Iterator<PointerKey> rts = escapeAnalysisRoots.iterator(); rts.hasNext();) {
       PointerKey root = rts.next();
-      OrdinalSet<InstanceKey> objects = pa.getPointsToSet(root);
-      for (Iterator<InstanceKey> objs = objects.iterator(); objs.hasNext();) {
+      OrdinalSet<? extends InstanceKey> objects = pa.getPointsToSet(root);
+      for (Iterator<? extends InstanceKey> objs = objects.iterator(); objs.hasNext();) {
         InstanceKey obj = (InstanceKey) objs.next();
         escapingInstanceKeys.add(obj);
       }
@@ -276,8 +276,8 @@ public class SimpleThreadEscapeAnalysis extends AbstractAnalysisEngine {
           if (type.isArrayClass()) {
             if (((ArrayClass) type).getElementClass() != null) {
               PointerKey fk = heapModel.getPointerKeyForArrayContents(key);
-              OrdinalSet<InstanceKey> fobjects = pa.getPointsToSet(fk);
-              for (Iterator<InstanceKey> fobjs = fobjects.iterator(); fobjs.hasNext();) {
+              OrdinalSet<? extends InstanceKey> fobjects = pa.getPointsToSet(fk);
+              for (Iterator<? extends InstanceKey> fobjs = fobjects.iterator(); fobjs.hasNext();) {
                 InstanceKey fobj = (InstanceKey) fobjs.next();
                 if (!escapingInstanceKeys.contains(fobj)) {
                   newKeys.add(fobj);
@@ -290,8 +290,8 @@ public class SimpleThreadEscapeAnalysis extends AbstractAnalysisEngine {
               IField f = (IField) fs.next();
               if (f.getFieldTypeReference().isReferenceType()) {
                 PointerKey fk = heapModel.getPointerKeyForInstanceField(key, f);
-                OrdinalSet<InstanceKey> fobjects = pa.getPointsToSet(fk);
-                for (Iterator<InstanceKey> fobjs = fobjects.iterator(); fobjs.hasNext();) {
+                OrdinalSet<? extends InstanceKey> fobjects = pa.getPointsToSet(fk);
+                for (Iterator<? extends InstanceKey> fobjs = fobjects.iterator(); fobjs.hasNext();) {
                   InstanceKey fobj = (InstanceKey) fobjs.next();
                   if (!escapingInstanceKeys.contains(fobj)) {
                     newKeys.add(fobj);
diff --git a/com.ibm.wala.core/src/com/ibm/wala/analysis/pointers/BasicHeapGraph.java b/com.ibm.wala.core/src/com/ibm/wala/analysis/pointers/BasicHeapGraph.java
index 4f2fa9cd5..a9193d833 100644
--- a/com.ibm.wala.core/src/com/ibm/wala/analysis/pointers/BasicHeapGraph.java
+++ b/com.ibm.wala.core/src/com/ibm/wala/analysis/pointers/BasicHeapGraph.java
@@ -256,10 +256,10 @@ public class BasicHeapGraph extends HeapGraph {
   private int[] computeSuccNodeNumbers(Object N, NumberedNodeManager<Object> nodeManager) {
     if (N instanceof PointerKey) {
       PointerKey P = (PointerKey) N;
-      OrdinalSet<InstanceKey> S = getPointerAnalysis().getPointsToSet(P);
+      OrdinalSet<? extends InstanceKey> S = getPointerAnalysis().getPointsToSet(P);
       int[] result = new int[S.size()];
       int i = 0;
-      for (Iterator<InstanceKey> it = S.iterator(); it.hasNext();) {
+      for (Iterator<? extends InstanceKey> it = S.iterator(); it.hasNext();) {
         result[i] = nodeManager.getNumber(it.next());
         i++;
       }
diff --git a/com.ibm.wala.core/src/com/ibm/wala/demandpa/alg/DemandRefinementPointsTo.java b/com.ibm.wala.core/src/com/ibm/wala/demandpa/alg/DemandRefinementPointsTo.java
index aa79d68a6..0d4a3006b 100644
--- a/com.ibm.wala.core/src/com/ibm/wala/demandpa/alg/DemandRefinementPointsTo.java
+++ b/com.ibm.wala.core/src/com/ibm/wala/demandpa/alg/DemandRefinementPointsTo.java
@@ -2459,7 +2459,7 @@ public class DemandRefinementPointsTo extends AbstractDemandPointsTo {
 
   private boolean predHoldsForPk(PointerKey curPk, Predicate<InstanceKey> pred, PointerAnalysis pa) {
     PointerKey curPkForPAHeapModel = convertToHeapModel(curPk, pa.getHeapModel());
-    OrdinalSet<InstanceKey> pointsToSet = pa.getPointsToSet(curPkForPAHeapModel);
+    OrdinalSet<? extends InstanceKey> pointsToSet = pa.getPointsToSet(curPkForPAHeapModel);
     for (InstanceKey ik : pointsToSet) {
       if (!pred.test(ik)) {
         return false;
diff --git a/com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/PointerAnalysis.java b/com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/PointerAnalysis.java
index 4362f4649..219dab61f 100644
--- a/com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/PointerAnalysis.java
+++ b/com.ibm.wala.core/src/com/ibm/wala/ipa/callgraph/propagation/PointerAnalysis.java
@@ -27,7 +27,7 @@ public interface PointerAnalysis {
    * @return Set of InstanceKey, representing the instance abstractions that define
    * the points-to set computed for the pointer key
    */
-  OrdinalSet<InstanceKey> getPointsToSet(PointerKey key);
+  OrdinalSet<? extends InstanceKey> getPointsToSet(PointerKey key);
 
   /**
    * @return an Object that determines how to model abstract locations in the heap.