diff --git a/src/machine.cpp b/src/machine.cpp
index 3d2afc4355..a5ed75a822 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -177,16 +177,22 @@ postVisit(Thread* t, Heap::Visitor* v)
     if (m->heap->status(*p) == Heap::Unreachable) {
       // reference is unreachable - remove it from the list
 
+      fprintf(stderr, "unreachable wr: %p\n", *p);
+
       *p = jreferenceNext(t, *p);
     } else if (m->heap->status(jreferenceTarget(t, *p)) == Heap::Unreachable) {
       // target is unreachable - clear the reference and remove it
       // from the list
 
+      fprintf(stderr, "target unreachable for wr: %p\n", *p);
+
       jreferenceTarget(t, *p) = 0;
       *p = jreferenceNext(t, *p);
     } else {
       // both reference and target are reachable
 
+      fprintf(stderr, "viable wr: %p\n", *p);
+
       v->visit(&jreferenceTarget(t, *p));
       v->visit(p);
 
@@ -341,14 +347,6 @@ collect(Thread* t, Heap::CollectionType type)
         cast<uintptr_t>(dst, 0) |= ExtendedMark;
         extendedWord(t, dst, base) = takeHash(t, o);
       }
-
-      if (classVmFlags(t, class_) & WeakReferenceFlag) {
-        fprintf(stderr, "weak reference to %p at %p\n",
-                jreferenceTarget(t, dst),
-                &jreferenceTarget(t, dst));
-        jreferenceNext(t, dst) = m->weakReferences;
-        m->weakReferences = dst;
-      }
     }
 
     virtual void walk(void* p, Heap::Walker* w) {
@@ -482,6 +480,7 @@ Machine::Machine(System* system, Heap* heap, ClassFinder* classFinder):
   finalizers(0),
   tenuredFinalizers(0),
   finalizeQueue(0),
+  weakReferences(0),
   tenuredWeakReferences(0),
   unsafe(false)
 {
@@ -998,6 +997,10 @@ objectMonitor(Thread* t, object o)
   object p = hashMapFind(t, t->vm->monitorMap, o, objectHash, referenceEqual);
 
   if (p) {
+    fprintf(stderr, "found monitor %p for object 0x%x\n",
+            static_cast<System::Monitor*>(pointerValue(t, p)),
+            objectHash(t, o));
+
     return static_cast<System::Monitor*>(pointerValue(t, p));
   } else {
     PROTECT(t, o);
@@ -1011,7 +1014,13 @@ objectMonitor(Thread* t, object o)
     p = makePointer(t, m);
     PROTECT(t, p);
 
-    object wr = makeWeakReference(t, o, 0);
+    object wr = makeWeakReference(t, o, t->vm->weakReferences);
+    t->vm->weakReferences = wr;
+
+    fprintf(stderr, "made monitor %p for object 0x%x\n",
+            m,
+            objectHash(t, o));
+    fprintf(stderr, "new wr: %p\n", wr);
 
     hashMapInsert(t, t->vm->monitorMap, wr, p, referenceHash);
 
diff --git a/src/machine.h b/src/machine.h
index b4866ad459..ad680c71ad 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -23,8 +23,8 @@ namespace vm {
 
 const bool Verbose = false;
 const bool Debug = false;
-const bool DebugRun = true;
-const bool DebugStack = true;
+const bool DebugRun = false;
+const bool DebugStack = false;
 
 const uintptr_t HashTakenMark = 1;
 const uintptr_t ExtendedMark = 2;
@@ -1644,13 +1644,6 @@ hash(const int8_t* s, unsigned length)
 inline unsigned
 baseSize(Thread* t, object o, object class_)
 {
-  if (classArrayElementSize(t, class_)) {
-    noop();
-    if (cast<uintptr_t>(o, classFixedSize(t, class_) - BytesPerWord)) {
-      noop();
-    }
-  }
-
   return divide(classFixedSize(t, class_), BytesPerWord)
     + divide(classArrayElementSize(t, class_)
              * cast<uintptr_t>(o, classFixedSize(t, class_) - BytesPerWord),