diff --git a/Makefile b/Makefile
index 36c558cff..c63b19041 100644
--- a/Makefile
+++ b/Makefile
@@ -72,7 +72,7 @@ CLD=c++ $(CFLAGS) -L/usr/local/lib $(OPTLOCALLFLAGS) $(OPENSSLLFLAGS)
 
 ifeq ($(OS),osx)
   CLDOSFLAGS=-bind_at_load
-  OSLIBS=-framework CoreServices -framework CoreFoundation
+  OSLIBS=-lprofiler -framework CoreServices -framework CoreFoundation
 endif
 ifeq ($(OS),linux)
   OSLIBS=-lpthread -lrt -lcurses
diff --git a/include/noun/allocate.h b/include/noun/allocate.h
index aec2662f0..1549948f8 100644
--- a/include/noun/allocate.h
+++ b/include/noun/allocate.h
@@ -400,6 +400,11 @@
           void
           u3a_print_memory(c3_c* cap_c, c3_w wor_w);
 
+        /* u3a_deadbeef(): write 0xdeadbeef from hat to cap.
+        */
+          void
+          u3a_deadbeef(void);
+
       /* Atoms from proto-atoms.
       */
         /* u3a_slab(): create a length-bounded proto-atom.
diff --git a/include/noun/trace.h b/include/noun/trace.h
index e629639c8..5b847f521 100644
--- a/include/noun/trace.h
+++ b/include/noun/trace.h
@@ -6,7 +6,7 @@
   **/
     /* U3_CPU_DEBUG: activate profiling.
     */
-#     define U3_CPU_DEBUG
+#     undef U3_CPU_DEBUG
 
   /** Data structures.
   **/
diff --git a/noun/allocate.c b/noun/allocate.c
index b0238276a..9c18b58b8 100644
--- a/noun/allocate.c
+++ b/noun/allocate.c
@@ -662,7 +662,7 @@ u3a_malloc(size_t len_i)
 
 /* u3a_cellblock(): allocate a block of cells on the hat.
 */
-c3_o
+static c3_o
 u3a_cellblock(c3_w num_w)
 {
   u3p(u3a_fbox) fre_p;
@@ -758,10 +758,7 @@ u3a_celloc(void)
       return u3a_walloc(c3_wiseof(u3a_cell));
     } 
     else {
-#ifdef U3_CPU_DEBUG
-        u3R->pro.cel_d++;
-#endif  
-      if ( c3n == u3a_cellblock(1024) ) {
+      if ( c3n == u3a_cellblock(256 << 10) ) {
         return u3a_walloc(c3_wiseof(u3a_cell));
       }
       cel_p = u3R->all.cel_p;
diff --git a/noun/imprison.c b/noun/imprison.c
index fc667e004..c08e967f4 100644
--- a/noun/imprison.c
+++ b/noun/imprison.c
@@ -204,7 +204,7 @@ u3i_cell(u3_noun a, u3_noun b)
 
 #ifdef U3_CPU_DEBUG
   u3R->pro.cel_d++;
-#endif
+#endif  
   {
     // c3_w*       nov_w = u3a_walloc(c3_wiseof(u3a_cell));
     c3_w*       nov_w = u3a_celloc();