diff --git a/com.ibm.wala.cast/source/java/com/ibm/wala/cast/ipa/callgraph/DelegatingAstPointerKeys.java b/com.ibm.wala.cast/source/java/com/ibm/wala/cast/ipa/callgraph/DelegatingAstPointerKeys.java
index 8cffa1e27..40351f009 100644
--- a/com.ibm.wala.cast/source/java/com/ibm/wala/cast/ipa/callgraph/DelegatingAstPointerKeys.java
+++ b/com.ibm.wala.cast/source/java/com/ibm/wala/cast/ipa/callgraph/DelegatingAstPointerKeys.java
@@ -106,8 +106,8 @@ public class DelegatingAstPointerKeys implements AstPointerKeyFactory {
   protected PointerKey getInstanceFieldPointerKeyForConstant(InstanceKey I, ConstantKey<?> F) {
     Object v = F.getValue();
     // FIXME: current only constant string are handled
-    if (v instanceof String) {
-      IField f = I.getConcreteType().getField(Atom.findOrCreateUnicodeAtom((String) v));
+    if (I.getConcreteType().getClassLoader().getLanguage().modelConstant(v)) {
+      IField f = I.getConcreteType().getField(Atom.findOrCreateUnicodeAtom(String.valueOf(v)));
       return getPointerKeyForInstanceField(I, f);
     }
     return null;
diff --git a/com.ibm.wala.core/src/com/ibm/wala/classLoader/Language.java b/com.ibm.wala.core/src/com/ibm/wala/classLoader/Language.java
index 88c9a4fd9..1ceb63be4 100644
--- a/com.ibm.wala.core/src/com/ibm/wala/classLoader/Language.java
+++ b/com.ibm.wala.core/src/com/ibm/wala/classLoader/Language.java
@@ -154,4 +154,7 @@ public interface Language {
   AbstractRootMethod getFakeRootMethod(IClassHierarchy cha, AnalysisOptions options, IAnalysisCacheView cache);
  
   InducedCFG makeInducedCFG(SSAInstruction[] instructions, IMethod method, Context context);
+  
+  boolean modelConstant(Object o);
+  
 }
diff --git a/com.ibm.wala.core/src/com/ibm/wala/classLoader/LanguageImpl.java b/com.ibm.wala.core/src/com/ibm/wala/classLoader/LanguageImpl.java
index 71a9b507f..d74c62492 100644
--- a/com.ibm.wala.core/src/com/ibm/wala/classLoader/LanguageImpl.java
+++ b/com.ibm.wala.core/src/com/ibm/wala/classLoader/LanguageImpl.java
@@ -74,4 +74,11 @@ public abstract class LanguageImpl implements Language {
   InducedCFG makeInducedCFG(SSAInstruction[] instructions, IMethod method, Context context) {
     return new InducedCFG(instructions, method, context);
   }
+
+  @Override
+  public boolean modelConstant(Object o) {
+    return o instanceof String;
+  }
+  
+  
 }