diff --git a/src/mzscheme/gc2/blame_the_child.c b/src/mzscheme/gc2/blame_the_child.c
index 21fb5c08bf..5b8a21e8c7 100644
--- a/src/mzscheme/gc2/blame_the_child.c
+++ b/src/mzscheme/gc2/blame_the_child.c
@@ -4,6 +4,13 @@
 #ifdef NEWGC_BTC_ACCOUNT
 
 #include "../src/schpriv.h"
+/* BTC_ prefixed functions are called by newgc.c */
+/* btc_ prefixed functions are internal to blame_the_child.c */
+
+static const int btc_redirect_thread    = 511;
+static const int btc_redirect_custodian = 510;
+static const int btc_redirect_ephemeron = 509;
+static const int btc_redirect_cust_box  = 508;
 
 /*****************************************************************************/
 /* thread list                                                               */
@@ -36,11 +43,12 @@ inline static void BTC_register_thread(void *t, void *c)
 inline static void mark_threads(NewGC *gc, int owner)
 {
   GC_Thread_Info *work;
+  Mark_Proc thread_mark = gc->mark_table[btc_redirect_thread];
 
   for(work = gc->thread_infos; work; work = work->next)
     if(work->owner == owner) {
       if (((Scheme_Thread *)work->thread)->running) {
-        gc->normal_thread_mark(work->thread);
+        thread_mark(work->thread);
         if (work->thread == scheme_current_thread) {
           GC_mark_variable_stack(GC_variable_stack, 0, get_stack_base(gc), NULL);
         }
@@ -249,6 +257,7 @@ inline static void mark_cust_boxes(NewGC *gc, Scheme_Custodian *cur)
 {
   Scheme_Object *pr, *prev = NULL, *next;
   GC_Weak_Box *wb;
+  Mark_Proc cust_box_mark = gc->mark_table[btc_redirect_cust_box];
 
   /* cust boxes is a list of weak boxes to cust boxes */
 
@@ -257,7 +266,7 @@ inline static void mark_cust_boxes(NewGC *gc, Scheme_Custodian *cur)
     wb = (GC_Weak_Box *)SCHEME_CAR(pr);
     next = SCHEME_CDR(pr);
     if (wb->val) {
-      gc->normal_cust_box_mark(wb->val);
+      cust_box_mark(wb->val);
       prev = pr;
     } else {
       if (prev)
@@ -273,21 +282,32 @@ inline static void mark_cust_boxes(NewGC *gc, Scheme_Custodian *cur)
 
 int BTC_thread_mark(void *p)
 {
-  return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  NewGC *gc = GC_get_GC();
+  if (gc->doing_memory_accounting) {
+    return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  }
+  return gc->mark_table[btc_redirect_thread](p);
 }
 
 int BTC_custodian_mark(void *p)
 {
   NewGC *gc = GC_get_GC();
-  if(custodian_to_owner_set(gc, p) == gc->current_mark_owner)
-    return gc->normal_custodian_mark(p);
-  else
-    return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  if (gc->doing_memory_accounting) {
+    if(custodian_to_owner_set(gc, p) == gc->current_mark_owner)
+      return gc->mark_table[btc_redirect_custodian](p);
+    else
+      return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  }
+  return gc->mark_table[btc_redirect_custodian](p);
 }
 
 int BTC_cust_box_mark(void *p)
 {
-  return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  NewGC *gc = GC_get_GC();
+  if (gc->doing_memory_accounting) {
+    return ((struct objhead *)(NUM(p) - WORD_SIZE))->size;
+  }
+  return gc->mark_table[btc_redirect_cust_box](p);
 }
 
 inline static void mark_normal_obj(NewGC *gc, mpage *page, void *ptr)
@@ -375,6 +395,21 @@ static void propagate_accounting_marks(NewGC *gc)
     reset_pointer_stack();
 }
 
+inline static void BTC_initialize_mark_table(NewGC *gc) {
+  gc->mark_table[scheme_thread_type]    = BTC_thread_mark;
+  gc->mark_table[scheme_custodian_type] = BTC_custodian_mark;
+  gc->mark_table[gc->ephemeron_tag]     = BTC_ephemeron_mark;
+  gc->mark_table[gc->cust_box_tag]      = BTC_cust_box_mark;
+}
+
+inline static int BTC_get_redirect_tag(NewGC *gc, int tag) {
+  if (tag == scheme_thread_type )         { tag = btc_redirect_thread; }
+  else if (tag == scheme_custodian_type ) { tag = btc_redirect_custodian; }
+  else if (tag == gc->ephemeron_tag )     { tag = btc_redirect_ephemeron; }
+  else if (tag == gc->cust_box_tag )      { tag = btc_redirect_cust_box; }
+  return tag;
+}
+
 static void BTC_do_accounting(NewGC *gc)
 {
   const int table_size = gc->owner_table_size;
@@ -390,17 +425,6 @@ static void BTC_do_accounting(NewGC *gc)
     gc->in_unsafe_allocation_mode = 1;
     gc->unsafe_allocation_abort = btc_overmem_abort;
 
-    if(!gc->normal_thread_mark) {
-      gc->normal_thread_mark    = gc->mark_table[scheme_thread_type];
-      gc->normal_custodian_mark = gc->mark_table[scheme_custodian_type];
-      gc->normal_cust_box_mark  = gc->mark_table[gc->cust_box_tag];
-    }
-
-    gc->mark_table[scheme_thread_type]    = BTC_thread_mark;
-    gc->mark_table[scheme_custodian_type] = BTC_custodian_mark;
-    gc->mark_table[gc->ephemeron_tag]     = BTC_ephemeron_mark;
-    gc->mark_table[gc->cust_box_tag]      = BTC_cust_box_mark;
-
     /* clear the memory use numbers out */
     for(i = 1; i < table_size; i++)
       if(owner_table[i])
@@ -427,11 +451,6 @@ static void BTC_do_accounting(NewGC *gc)
       box = cur->global_prev; cur = box ? SCHEME_PTR1_VAL(box) : NULL;
     }
 
-    gc->mark_table[scheme_thread_type]    = gc->normal_thread_mark;
-    gc->mark_table[scheme_custodian_type] = gc->normal_custodian_mark;
-    gc->mark_table[gc->ephemeron_tag]     = mark_ephemeron;
-    gc->mark_table[gc->cust_box_tag]      = gc->normal_cust_box_mark;
-
     gc->in_unsafe_allocation_mode = 0;
     gc->doing_memory_accounting = 0;
     gc->old_btc_mark = gc->new_btc_mark;
diff --git a/src/mzscheme/gc2/newgc.c b/src/mzscheme/gc2/newgc.c
index c6bce7a3cf..6af7710f8f 100644
--- a/src/mzscheme/gc2/newgc.c
+++ b/src/mzscheme/gc2/newgc.c
@@ -1447,16 +1447,16 @@ void GC_write_barrier(void *p)
 #include "sighand.c"
 
 void NewGC_initialize(NewGC *newgc, NewGC *parentgc) {
-  memset(newgc, 0, sizeof(NewGC));
   if (parentgc) {
-    newgc->mark_table  = ofm_malloc(NUMBER_OF_TAGS * sizeof (Mark_Proc)); 
-    newgc->fixup_table = ofm_malloc(NUMBER_OF_TAGS * sizeof (Fixup_Proc)); 
-    memcpy(newgc->mark_table,  parentgc->mark_table,  NUMBER_OF_TAGS * sizeof (Mark_Proc)); 
-    memcpy(newgc->fixup_table, parentgc->fixup_table, NUMBER_OF_TAGS * sizeof (Fixup_Proc)); 
+    newgc->mark_table  = parentgc->mark_table;
+    newgc->fixup_table = parentgc->fixup_table;
   }
   else {
     newgc->mark_table  = ofm_malloc_zero(NUMBER_OF_TAGS * sizeof (Mark_Proc)); 
     newgc->fixup_table = ofm_malloc_zero(NUMBER_OF_TAGS * sizeof (Fixup_Proc)); 
+# ifdef NEWGC_BTC_ACCOUNT
+    BTC_initialize_mark_table(newgc);
+#endif
   }
 
   mark_stack_initialize();
@@ -1480,10 +1480,9 @@ static NewGC *init_type_tags_worker(NewGC *parentgc, int count, int pair, int mu
 {
   NewGC *gc;
 
-  gc = ofm_malloc(sizeof(NewGC));
+  gc = ofm_malloc_zero(sizeof(NewGC));
   /* NOTE sets the constructed GC as the new Thread Specific GC. */
   GC_set_GC(gc);
-  NewGC_initialize(gc, parentgc);
 
   gc->weak_box_tag    = weakbox;
   gc->ephemeron_tag   = ephemeron;
@@ -1492,6 +1491,9 @@ static NewGC *init_type_tags_worker(NewGC *parentgc, int count, int pair, int mu
   gc->cust_box_tag    = custbox;
 # endif
 
+  NewGC_initialize(gc, parentgc);
+
+
   /* Our best guess at what the OS will let us allocate: */
   gc->max_pages_in_heap = determine_max_heap_size() / APAGE_SIZE;
   /* Not all of that memory is available for allocating GCable
@@ -1502,9 +1504,11 @@ static NewGC *init_type_tags_worker(NewGC *parentgc, int count, int pair, int mu
 
   resize_gen0(gc, GEN0_INITIAL_SIZE);
 
-  GC_register_traversers(gc->weak_box_tag, size_weak_box, mark_weak_box, fixup_weak_box, 0, 0);
-  GC_register_traversers(gc->ephemeron_tag, size_ephemeron, mark_ephemeron, fixup_ephemeron, 0, 0);
-  GC_register_traversers(gc->weak_array_tag, size_weak_array, mark_weak_array, fixup_weak_array, 0, 0);
+  if (!parentgc) {
+    GC_register_traversers(gc->weak_box_tag, size_weak_box, mark_weak_box, fixup_weak_box, 0, 0);
+    GC_register_traversers(gc->ephemeron_tag, size_ephemeron, mark_ephemeron, fixup_ephemeron, 0, 0);
+    GC_register_traversers(gc->weak_array_tag, size_weak_array, mark_weak_array, fixup_weak_array, 0, 0);
+  }
   initialize_signal_handler(gc);
   GC_add_roots(&gc->park, (char *)&gc->park + sizeof(gc->park) + 1);
   GC_add_roots(&gc->park_save, (char *)&gc->park_save + sizeof(gc->park_save) + 1);
@@ -1579,8 +1583,15 @@ void GC_register_traversers(short tag, Size_Proc size, Mark_Proc mark,
     Fixup_Proc fixup, int constant_Size, int atomic)
 {
   NewGC *gc = GC_get_GC();
-  gc->mark_table[tag]  = atomic ? (Mark_Proc)PAGE_ATOMIC : mark;
-  gc->fixup_table[tag] = fixup;
+
+  int mark_tag = tag;
+
+#ifdef NEWGC_BTC_ACCOUNT
+  mark_tag = BTC_get_redirect_tag(gc, mark_tag);
+#endif
+
+  gc->mark_table[mark_tag]  = atomic ? (Mark_Proc)PAGE_ATOMIC : mark;
+  gc->fixup_table[tag]      = fixup;
 }
 
 long GC_get_memory_use(void *o) 
diff --git a/src/mzscheme/gc2/newgc.h b/src/mzscheme/gc2/newgc.h
index 0c33f0bd18..435dae0d11 100644
--- a/src/mzscheme/gc2/newgc.h
+++ b/src/mzscheme/gc2/newgc.h
@@ -116,10 +116,7 @@ typedef struct NewGC {
   void (*unsafe_allocation_abort)(struct NewGC *);
   unsigned long memory_in_use; /* the amount of memory in use */
 
-  /* blame the child saved off Mark_Proc pointers */
-  Mark_Proc normal_thread_mark;
-  Mark_Proc normal_custodian_mark;
-  Mark_Proc normal_cust_box_mark;
+  /* blame the child thread infos */
   GC_Thread_Info *thread_infos;
 
   mpage *release_pages;
diff --git a/src/mzscheme/gc2/weak.c b/src/mzscheme/gc2/weak.c
index 719d5cceef..da95fb12a7 100644
--- a/src/mzscheme/gc2/weak.c
+++ b/src/mzscheme/gc2/weak.c
@@ -234,12 +234,17 @@ static int mark_ephemeron(void *p)
 #ifdef NEWGC_BTC_ACCOUNT
 static int BTC_ephemeron_mark(void *p)
 {
-  GC_Ephemeron *eph = (GC_Ephemeron *)p;
-  
-  gcMARK(eph->key);
-  gcMARK(eph->val);
+  GCTYPE *gc = GC_get_GC();
+  if (gc->doing_memory_accounting) {
 
-  return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
+    GC_Ephemeron *eph = (GC_Ephemeron *)p;
+
+    gcMARK(eph->key);
+    gcMARK(eph->val);
+
+    return gcBYTES_TO_WORDS(sizeof(GC_Ephemeron));
+  }
+  return mark_ephemeron(p);
 }
 #endif