diff --git a/include/haproxy/ring.h b/include/haproxy/ring.h
index 7fb9bc6b8..f8c3a52b6 100644
--- a/include/haproxy/ring.h
+++ b/include/haproxy/ring.h
@@ -60,12 +60,22 @@ static inline size_t ring_data(const struct ring *ring)
 		0 : ring->storage->size) + tail - ring->storage->head;
 }
 
-/* returns the allocated size in bytes for the ring */
+/* returns the usable size in bytes for the ring. It is smaller than
+ * the allocate size by the size of the ring_storage header.
+ */
 static inline size_t ring_size(const struct ring *ring)
 {
 	return ring->storage->size;
 }
 
+/* returns the allocated size in bytes for the ring. It covers the whole
+ * area made of both the ring_storage and the usable area.
+ */
+static inline size_t ring_allocated_size(const struct ring *ring)
+{
+	return ring->storage->size + ring->storage->rsvd;
+}
+
 /* returns the head offset of the ring */
 static inline size_t ring_head(const struct ring *ring)
 {
diff --git a/src/ring.c b/src/ring.c
index cc0e3a79d..16b8a4b02 100644
--- a/src/ring.c
+++ b/src/ring.c
@@ -104,7 +104,7 @@ struct ring *ring_make_from_area(void *area, size_t size, int reset)
 }
 
 /* Creates and returns a ring buffer of size <size> bytes. Returns NULL on
- * allocation failure.
+ * allocation failure. The size is the area size, not the usable size.
  */
 struct ring *ring_new(size_t size)
 {
@@ -114,7 +114,8 @@ struct ring *ring_new(size_t size)
 /* Resizes existing ring <ring> to <size> which must be larger, without losing
  * its contents. The new size must be at least as large as the previous one or
  * no change will be performed. The pointer to the ring is returned on success,
- * or NULL on allocation failure. This will lock the ring for writes.
+ * or NULL on allocation failure. This will lock the ring for writes. The size
+ * is the allocated area size, and includes the ring_storage header.
  */
 struct ring *ring_resize(struct ring *ring, size_t size)
 {