diff --git a/include/nuttx/mm/mm.h b/include/nuttx/mm/mm.h
index 4536200ec8..f448138dca 100644
--- a/include/nuttx/mm/mm.h
+++ b/include/nuttx/mm/mm.h
@@ -211,12 +211,10 @@ struct mm_freenode_s
   FAR struct mm_freenode_s *blink;
 };
 
-#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
 struct mm_delaynode_s
 {
   struct mm_delaynode_s *flink;
 };
-#endif
 
 /* What is the size of the freenode? */
 
@@ -258,11 +256,9 @@ struct mm_heap_s
 
   struct mm_freenode_s mm_nodelist[MM_NNODES];
 
-#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
   /* Free delay list, for some situation can't do free immdiately */
 
   struct mm_delaynode_s *mm_delaylist;
-#endif
 };
 
 /****************************************************************************
diff --git a/mm/mm_heap/mm_initialize.c b/mm/mm_heap/mm_initialize.c
index d96b7b16b9..fa41069b2f 100644
--- a/mm/mm_heap/mm_initialize.c
+++ b/mm/mm_heap/mm_initialize.c
@@ -175,11 +175,9 @@ void mm_initialize(FAR struct mm_heap_s *heap, FAR void *heapstart,
   heap->mm_nregions = 0;
 #endif
 
-#if defined(CONFIG_BUILD_FLAT) || defined(__KERNEL__)
   /* Initialize mm_delaylist */
 
   heap->mm_delaylist = NULL;
-#endif
 
   /* Initialize the node array */