diff --git a/include/common/buffer.h b/include/common/buffer.h
index f11d6a9..c6fb2fe 100644
--- a/include/common/buffer.h
+++ b/include/common/buffer.h
@@ -543,7 +543,7 @@
 		return 2;
 	}
 
-	*blk1 = buf->p - buf->o;
+	*blk1 = bo_ptr(buf);
 	*len1 = buf->o;
 	return 1;
 }