diff --git a/gc.c b/gc.c
index 6ceb823e..103afa85 100644
--- a/gc.c
+++ b/gc.c
@@ -57,6 +57,23 @@ void gc_init_mutators()
   }
 }
 
+// Add data for a new mutator
+void gc_add_mutator(gc_thread_data *thd)
+{
+  // TODO: need to sync access to these static variables. both here and
+  // elsewhere in the module!!
+  int i;
+  for (i = 0; i < Cyc_num_mutators; i++) {
+    if (!Cyc_mutators[i]) {
+      Cyc_mutators[i] = thd;
+      return;
+    }
+  }
+  // TODO: unable to create any more mutators. what to do???
+  fprintf(stderr, "Unable to create a new thread, exiting\n");
+  exit(1);
+}
+
 gc_heap *gc_heap_create(size_t size, size_t max_size, size_t chunk_size)
 {
   gc_free_list *free, *next;
diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index aaf8d84a..dbf06449 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -126,6 +126,7 @@ void vpbuffer_free(void **buf);
 
 /* GC prototypes */
 void gc_init_mutators();
+void gc_add_mutator(gc_thread_data *thd);
 gc_heap *gc_heap_create(size_t size, size_t max_size, size_t chunk_size);
 int gc_grow_heap(gc_heap *h, size_t size, size_t chunk_size);
 void *gc_try_alloc(gc_heap *h, size_t size);