diff --git a/src/mzscheme/src/places.c b/src/mzscheme/src/places.c
index 1350909fb2..ddd46842a3 100644
--- a/src/mzscheme/src/places.c
+++ b/src/mzscheme/src/places.c
@@ -18,6 +18,7 @@ static Scheme_Object *scheme_place_sleep(int argc, Scheme_Object *args[]);
 static Scheme_Object *scheme_place_p(int argc, Scheme_Object *args[]);
 static void load_namespace(char *namespace_name);
 static void load_namespace_utf8(Scheme_Object *namespace_name);
+static Scheme_Object *scheme_places_deep_copy_in_master(Scheme_Object *so);
 
 # ifdef MZ_PRECISE_GC
 static void register_traversers(void);
@@ -121,6 +122,7 @@ Scheme_Object *scheme_place(int argc, Scheme_Object *args[]) {
     scheme_wrong_count_m("place", 1, 2, argc, args, 0);
   }
   collection_paths = scheme_current_library_collection_paths(0, NULL);
+  collection_paths = scheme_places_deep_copy_in_master(collection_paths);
   place_data->current_library_collection_paths = collection_paths;
 
   /* create new place */
@@ -188,6 +190,20 @@ Scheme_Object *scheme_places_deep_copy(Scheme_Object *so)
         new_so = scheme_intern_exact_symbol(sym->s, sym->len);
       }
       break;
+    case scheme_pair_type:
+      {
+        Scheme_Object *car;
+        Scheme_Object *cdr;
+        Scheme_Object *pair;
+        car = scheme_places_deep_copy(SCHEME_CAR(so));
+        cdr = scheme_places_deep_copy(SCHEME_CDR(so));
+        pair = scheme_make_pair(car, cdr);
+        return pair;
+      }
+      break;
+    case scheme_null_type:
+      new_so = so;
+      break;
     case scheme_resolved_module_path_type:
       abort();
       break;
@@ -243,8 +259,21 @@ static void *place_start_proc(void *data_arg) {
   return scheme_true;
 }
 
-#ifdef MZ_PRECISE_GC
+Scheme_Object *scheme_places_deep_copy_in_master(Scheme_Object *so) {
+#if defined(MZ_USE_PLACES) && defined(MZ_PRECISE_GC)
+    mz_proc_thread *self;
+    self = proc_thread_self;
+    if ( scheme_master_proc_thread && scheme_master_proc_thread != proc_thread_self ) {
+      int return_msg_type;
+      void *return_payload;
+      pt_mbox_send_recv(scheme_master_proc_thread->mbox, 5, so, self->mbox, &return_msg_type, &return_payload);
+      return (Scheme_Object*) return_payload;
+    }
+#endif
+  return so;
+}
 
+#ifdef MZ_PRECISE_GC
 static void *master_scheme_place(void *data) {
   mz_proc_thread *myself;
   myself = proc_thread_self;
@@ -273,6 +302,8 @@ static void *master_scheme_place(void *data) {
         }
         break;
       case 5:
+        copied_o = scheme_places_deep_copy((Scheme_Object *)recv_payload);
+        pt_mbox_send(origin, 6, (void *) copied_o, NULL);
         break;
     }
   }