diff --git a/include/malloc.h b/include/malloc.h
index a38464e..0382169 100644
--- a/include/malloc.h
+++ b/include/malloc.h
@@ -937,6 +937,12 @@
 struct mallinfo mALLINFo();
 #endif
 
+/*
+ * Begin and End of memory area for malloc(), and current "brk"
+ */
+extern ulong mem_malloc_start;
+extern ulong mem_malloc_end;
+extern ulong mem_malloc_brk;
 
 #ifdef __cplusplus
 };  /* end of extern "C" */