diff --git a/mm/mm_heap/mm_initialize.c b/mm/mm_heap/mm_initialize.c
index 414aa96f11..676f1901f4 100644
--- a/mm/mm_heap/mm_initialize.c
+++ b/mm/mm_heap/mm_initialize.c
@@ -65,7 +65,7 @@ static FAR void *mempool_memalign(FAR void *arg, size_t alignment,
   if (ret)
     {
       node = (FAR struct mm_allocnode_s *)
-      ((FAR char *)ret - MM_SIZEOF_ALLOCNODE);
+      ((uintptr_t)ret - MM_SIZEOF_ALLOCNODE);
       node->pid = PID_MM_MEMPOOL;
     }