diff --git a/runtime.h b/runtime.h
index 7849290f..5195db64 100644
--- a/runtime.h
+++ b/runtime.h
@@ -1491,9 +1491,9 @@ static void GC_loop(int major, closure cont, object *ans, int num_ans)
     dhalloc_end = dhallocp + global_heap_size - 8;
  }
 
-//#if DEBUG_GC
+#if DEBUG_GC
  printf("\n=== started GC type = %d === \n", major);
-//#endif
+#endif
  /* Transport GC's continuation and its argument. */
  transp(cont);
  gc_cont = cont;
@@ -1720,9 +1720,9 @@ static void main_main (stack_size,heap_size,stack_base)
 
   /* Tank, load the jump program... */
   setjmp(jmp_main);
-//#if DEBUG_GC
+#if DEBUG_GC
   printf("Done with GC\n");
-//#endif
+#endif
   do_dispatch(gc_num_ans, ((closure)gc_cont)->fn, gc_cont, gc_ans);
 
   /*                                                                      */