diff --git a/openflow_input/standard-1.3 b/openflow_input/standard-1.3
index 061f9ce6d..67ae21b68 100644
--- a/openflow_input/standard-1.3
+++ b/openflow_input/standard-1.3
@@ -597,7 +597,7 @@ struct of_hello_elem {
     uint16_t length;
 };
 
-struct of_hello_elem_versionbitmap : of_hello_elem {
+struct of_hello_elem_versionbitmap(align=8) : of_hello_elem {
     uint16_t type == 1;
     uint16_t length;
     list(of_uint32_t) bitmaps;
diff --git a/openflow_input/standard-1.4 b/openflow_input/standard-1.4
index 51a1a1906..f33c0819c 100644
--- a/openflow_input/standard-1.4
+++ b/openflow_input/standard-1.4
@@ -727,7 +727,7 @@ struct of_hello_elem {
     uint16_t length;
 };
 
-struct of_hello_elem_versionbitmap : of_hello_elem {
+struct of_hello_elem_versionbitmap(align=8) : of_hello_elem {
     uint16_t type == 1;
     uint16_t length;
     list(of_uint32_t) bitmaps;
diff --git a/openflow_input/standard-1.5 b/openflow_input/standard-1.5
index a875c5ad7..a4bbf6a32 100644
--- a/openflow_input/standard-1.5
+++ b/openflow_input/standard-1.5
@@ -2917,7 +2917,7 @@ struct of_hello_elem {
 };
 
 /* Version bitmap Hello Element */
-struct of_hello_elem_versionbitmap : of_hello_elem {
+struct of_hello_elem_versionbitmap(align=8) : of_hello_elem {
     uint16_t type == 1;
     uint16_t length;
     list(of_uint32_t) bitmaps;