diff --git a/include/haproxy/htx.h b/include/haproxy/htx.h
index 31bbcd982..7cc5ffe60 100644
--- a/include/haproxy/htx.h
+++ b/include/haproxy/htx.h
@@ -307,6 +307,16 @@ static inline struct htx_blk *htx_get_next_blk(const struct htx *htx,
 	return ((pos == -1) ? NULL : htx_get_blk(htx, pos));
 }
 
+/* Returns 1 if <blk> is the block is the only one inside the HTX message <htx>,
+ * excluding all unsued blocks. Otherwise, it returns 0. If 1 is returned, this
+ * means that there is only <blk> and eventually some unused ones in <htx>.
+ */
+static inline int htx_is_unique_blk(const struct htx *htx,
+				    const struct htx_blk *blk)
+{
+	return (htx_get_blksz(blk) == htx->data);
+}
+
 /* Changes the size of the value. It is the caller responsibility to change the
  * value itself, make sure there is enough space and update allocated
  * value. This function updates the HTX message accordingly.