diff --git a/src/foreign/foreign.c b/src/foreign/foreign.c
index 4aa17bec7b..830ce35e92 100644
--- a/src/foreign/foreign.c
+++ b/src/foreign/foreign.c
@@ -1964,7 +1964,9 @@ static Scheme_Object *foreign_free(int argc, Scheme_Object *argv[])
 #define MYNAME "malloc-immobile-cell"
 static Scheme_Object *foreign_malloc_immobile_cell(int argc, Scheme_Object *argv[])
 {
-  return scheme_make_foreign_external_cpointer(scheme_malloc_immobile_box(argv[0]));
+  void *p;
+  p = scheme_malloc_immobile_box(argv[0]);
+  return scheme_make_foreign_external_cpointer(p); /* <- beware: macro duplicates `p' */
 }
 #undef MYNAME
 
diff --git a/src/foreign/foreign.rktc b/src/foreign/foreign.rktc
index d898d62f54..1984a59f23 100755
--- a/src/foreign/foreign.rktc
+++ b/src/foreign/foreign.rktc
@@ -1387,7 +1387,9 @@ static void* SCHEME2C(Scheme_Object *type, void *dst, long delta,
 
 /* (malloc-immobile-cell v) */
 @cdefine[malloc-immobile-cell 1]{
-  return scheme_make_foreign_external_cpointer(scheme_malloc_immobile_box(argv[0]));
+  void *p;
+  p = scheme_malloc_immobile_box(argv[0]);
+  return scheme_make_foreign_external_cpointer(p); /* <- beware: macro duplicates `p' */
 }
 
 /* (free-immobile-cell b) */
diff --git a/src/racket/gc2/newgc.c b/src/racket/gc2/newgc.c
index 75e5f2de35..f9901a752b 100644
--- a/src/racket/gc2/newgc.c
+++ b/src/racket/gc2/newgc.c
@@ -2854,7 +2854,8 @@ void GC_dump_with_traces(int flags,
 {
   NewGC *gc = GC_get_GC();
   mpage *page;
-  int i;
+  int i, num_immobiles;
+  GC_Immobile_Box *ib;
   static unsigned long counts[MAX_DUMP_TAG], sizes[MAX_DUMP_TAG];
 
   reset_object_traces();
@@ -2934,6 +2935,10 @@ void GC_dump_with_traces(int flags,
     }
   }
 
+  num_immobiles = 0;
+  for (ib = gc->immobile_boxes; ib; ib = ib->next)
+    num_immobiles++;
+
   GCPRINT(GCOUTF, "Begin Racket3m\n");
   for (i = 0; i < MAX_DUMP_TAG; i++) {
     if (counts[i]) {
@@ -2998,6 +3003,7 @@ void GC_dump_with_traces(int flags,
   GCWARN((GCOUTF,"# of minor collections: %li\n", gc->num_minor_collects));
   GCWARN((GCOUTF,"# of installed finalizers: %i\n", gc->num_fnls));
   GCWARN((GCOUTF,"# of traced ephemerons: %i\n", gc->num_last_seen_ephemerons));
+  GCWARN((GCOUTF,"# of immobile boxes: %i\n", num_immobiles));
 
   if (flags & GC_DUMP_SHOW_TRACE) {
     print_traced_objects(path_length_limit, get_type_name, get_xtagged_name, print_tagged_value);