diff --git a/contrib/spoa_example/include/mini-clist.h b/contrib/spoa_example/include/mini-clist.h
index a89255c..d009704 100644
--- a/contrib/spoa_example/include/mini-clist.h
+++ b/contrib/spoa_example/include/mini-clist.h
@@ -44,7 +44,7 @@
  * since it's used only once.
  * Example: LIST_ELEM(cur_node->args.next, struct node *, args)
  */
-#define LIST_ELEM(lh, pt, el) ((pt)(((void *)(lh)) - ((void *)&((pt)NULL)->el)))
+#define LIST_ELEM(lh, pt, el) ((pt)(((const char *)(lh)) - ((size_t)&((pt)NULL)->el)))
 
 /* checks if the list head <lh> is empty or not */
 #define LIST_ISEMPTY(lh) ((lh)->n == (lh))
diff --git a/include/common/mini-clist.h b/include/common/mini-clist.h
index 592bb96..501904b 100644
--- a/include/common/mini-clist.h
+++ b/include/common/mini-clist.h
@@ -106,7 +106,7 @@
  * since it's used only once.
  * Example: LIST_ELEM(cur_node->args.next, struct node *, args)
  */
-#define LIST_ELEM(lh, pt, el) ((pt)(((void *)(lh)) - ((void *)&((pt)NULL)->el)))
+#define LIST_ELEM(lh, pt, el) ((pt)(((const char *)(lh)) - ((size_t)&((pt)NULL)->el)))
 
 /* checks if the list head <lh> is empty or not */
 #define LIST_ISEMPTY(lh) ((lh)->n == (lh))