diff --git a/gc.c b/gc.c
index 0d190161..a69c2fc1 100644
--- a/gc.c
+++ b/gc.c
@@ -1753,22 +1753,6 @@ void gc_thr_grow_move_buffer(gc_thread_data * d)
 #endif
 }
 
-/**
- * @brief Add an object to the move buffer
- * @param d Mutator data object containing the buffer
- * @param alloci  Pointer to the next open slot in the buffer
- * @param obj     Object to add
- */
-void gc_thr_add_to_move_buffer(gc_thread_data * d, int *alloci, object obj)
-{
-  if (*alloci == d->moveBufLen) {
-    gc_thr_grow_move_buffer(d);
-  }
-
-  d->moveBuf[*alloci] = obj;
-  (*alloci)++;
-}
-
 // END heap definitions
 
 // Tri-color GC section
diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index 5e597653..e880af0b 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -381,7 +381,6 @@ void gc_mark_globals(object globals, object global_table);
 //size_t gc_sweep(gc_heap * h, int heap_type, size_t * sum_freed_ptr, gc_thread_data *thd);
 gc_heap *gc_sweep(gc_heap * h, int heap_type, gc_thread_data *thd);
 void gc_thr_grow_move_buffer(gc_thread_data * d);
-void gc_thr_add_to_move_buffer(gc_thread_data * d, int *alloci, object obj);
 void gc_thread_data_init(gc_thread_data * thd, int mut_num, char *stack_base,
                          long stack_size);
 void gc_thread_data_free(gc_thread_data * thd);
diff --git a/runtime.c b/runtime.c
index 7678fba6..19179507 100644
--- a/runtime.c
+++ b/runtime.c
@@ -5325,7 +5325,23 @@ void gc_request_mark_globals(void)
   gc_mark_globals(Cyc_global_variables, global_table);
 }
 
-char *gc_fixup_moved_obj(gc_thread_data * thd, int *alloci, char *obj,
+/**
+ * @brief Add an object to the move buffer
+ * @param d Mutator data object containing the buffer
+ * @param alloci  Pointer to the next open slot in the buffer
+ * @param obj     Object to add
+ */
+static void gc_thr_add_to_move_buffer(gc_thread_data * d, int *alloci, object obj)
+{
+  if (*alloci == d->moveBufLen) {
+    gc_thr_grow_move_buffer(d);
+  }
+
+  d->moveBuf[*alloci] = obj;
+  (*alloci)++;
+}
+
+static char *gc_fixup_moved_obj(gc_thread_data * thd, int *alloci, char *obj,
                          object hp)
 {
   int acquired_lock = 0;