diff --git a/openflow_input/standard-1.3 b/openflow_input/standard-1.3
index b0aa242..ab94fd5 100644
--- a/openflow_input/standard-1.3
+++ b/openflow_input/standard-1.3
@@ -724,7 +724,7 @@
 };
 
 // FIXME Does this need to be v4?
-struct of_match_v3 {
+struct of_match_v3(align=8) {
     uint16_t type == 1;
     uint16_t length;
     list(of_oxm_t) oxm_list;