diff --git a/openflow_input/standard-1.2 b/openflow_input/standard-1.2
index f4d31d6..4ff23b7 100644
--- a/openflow_input/standard-1.2
+++ b/openflow_input/standard-1.2
@@ -598,7 +598,7 @@
     pad(4);
 };
 
-struct of_match_v3 {
+struct of_match_v3(align=8) {
     uint16_t type == 1;
     uint16_t length;
     list(of_oxm_t) oxm_list;