Index: src/pmc/resizablepmcarray.pmc
===================================================================
--- src/pmc/resizablepmcarray.pmc	(revision 16208)
+++ src/pmc/resizablepmcarray.pmc	(working copy)
@@ -205,8 +205,6 @@
         if (key >= PMC_int_val(SELF))
             DYNSELF.set_integer_native(key+1);
         data = PMC_data(SELF);
-        if (data[key] == PMCNULL)
-            data[key] = pmc_new(INTERP, enum_class_Undef);
         return data[key];
     }
 
Index: src/pmc/array.pmc
===================================================================
--- src/pmc/array.pmc	(revision 16208)
+++ src/pmc/array.pmc	(working copy)
@@ -22,25 +22,9 @@
 
 /*
 
-=item C<static PMC* undef(Interp* interp)>
-
-Returns a C<Undef> PMC.
-
-=cut
-
-*/
-
-static PMC* undef(Interp* interp)
-{
-    return pmc_new(interp, enum_class_Undef);
-}
-
-/*
-
 =item C<static PMC* retval(Interp *interp, void *ret)>
 
-Processes C<*ret>, returning the appropriate PMC, or raising an
-exception if necessary.
+Processes C<*ret>, returning PMCNULL if needed.
 
 =cut
 
@@ -48,20 +32,7 @@
 
 static PMC* retval(Interp *interp, void *ret)
 {
-    PMC *value;
-    if (ret == 0)
-    real_exception(interp, NULL, E_IndexError,
-        "Array index out of bounds!");
-    /* XXX getting non existent value, exception or undef?
-     * current is for perlarray */
-    if (ret == (void*) -1)
-        value = undef(interp);
-    else {
-        value = *(PMC**) ret;
-        if (value == NULL)  /* XXX same here */
-            value = undef(interp);
-    }
-    return value;
+    return ret == 0 || ret == (void*) -1 ? PMCNULL : (PMC*)ret;
 }
 
 /*
@@ -88,7 +59,7 @@
             "Array index out of bounds!");
     /* assign into a sparse or not yet set value */
     if (ret == (void*) -1 || *(PMC**)ret == 0) {
-        value = undef(interp);
+        value = PMCNULL;
         list_assign(interp, list, key, value, enum_type_PMC);
     }
     else
@@ -348,7 +319,8 @@
         if (nextkey == NULL) return SELF.get_integer_keyed_int(ix);
 
         box = SELF.get_pmc_keyed_int(ix);
-        if (box == NULL) box = undef(INTERP);
+        if (box == NULL)
+            box = PMCNULL;
         return VTABLE_get_integer_keyed(INTERP, box, nextkey);
     }
 
@@ -391,7 +363,8 @@
         if (nextkey == NULL) return SELF.get_number_keyed_int(ix);
 
         box = SELF.get_pmc_keyed_int(ix);
-        if (box == NULL) box = undef(INTERP);
+        if (box == NULL)
+            box = PMCNULL;
         return VTABLE_get_number_keyed(INTERP, box, nextkey);
     }
 
@@ -433,7 +406,8 @@
         if (nextkey == NULL) return SELF.get_string_keyed_int(ix);
 
         box = SELF.get_pmc_keyed_int(ix);
-        if (box == NULL) box = undef(INTERP);
+        if (box == NULL)
+            box = PMCNULL;
         return VTABLE_get_string_keyed(INTERP, box, nextkey);
     }
 
@@ -473,7 +447,8 @@
         if (nextkey == NULL) return SELF.get_pmc_keyed_int(ix);
 
         box = SELF.get_pmc_keyed_int(ix);
-        if (box == NULL) box = undef(INTERP);
+        if (box == NULL)
+            box = PMCNULL;
         return VTABLE_get_pmc_keyed(INTERP, box, nextkey);
     }
 
@@ -774,7 +749,7 @@
 */
 
     void unshift_integer (INTVAL value) {
-        PMC * val = undef(INTERP);
+        PMC * val = PMCNULL;
         list_unshift(INTERP, (List*)PMC_data(SELF), val, enum_type_PMC);
         VTABLE_set_integer_native(INTERP, val, value);
     }
@@ -791,7 +766,7 @@
 */
 
     void unshift_float (FLOATVAL value) {
-        PMC * val = undef(INTERP);
+        PMC * val = PMCNULL;
         list_unshift(INTERP, (List*)PMC_data(SELF), val, enum_type_PMC);
         VTABLE_set_number_native(INTERP, val, value);
     }
@@ -808,7 +783,7 @@
 */
 
     void unshift_string (STRING *value) {
-        PMC * val = undef(INTERP);
+        PMC * val = PMCNULL;
         list_unshift(INTERP, (List*)PMC_data(SELF), val, enum_type_PMC);
         VTABLE_set_string_native(INTERP, val, value);
     }
@@ -1277,10 +1252,6 @@
 
 F<src/list.c>, F<include/parrot/list.h>
 
-=head1 TODO
-
-Create global immutable undef object.
-
 =cut
 
 */