diff --git a/modules/msg/mission_inc/default_cfe_msg_hdr_pri.h b/modules/msg/mission_inc/default_cfe_msg_hdr_pri.h
index 0e8558d5d..4ff9880bf 100644
--- a/modules/msg/mission_inc/default_cfe_msg_hdr_pri.h
+++ b/modules/msg/mission_inc/default_cfe_msg_hdr_pri.h
@@ -82,6 +82,7 @@ typedef struct
 
     CFE_MSG_Message_t                  Msg; /**< \brief Base message */
     CFE_MSG_TelemetrySecondaryHeader_t Sec; /**< \brief Secondary header */
+    uint8                              Spare[4]; /**< \brief Padding to end on 64 bit boundary */
 
 } CFE_MSG_TelemetryHeader_t;
 
diff --git a/modules/msg/mission_inc/default_cfe_msg_hdr_priext.h b/modules/msg/mission_inc/default_cfe_msg_hdr_priext.h
index aa401bd8b..36d9dccbe 100644
--- a/modules/msg/mission_inc/default_cfe_msg_hdr_priext.h
+++ b/modules/msg/mission_inc/default_cfe_msg_hdr_priext.h
@@ -72,6 +72,7 @@ typedef struct
 
     CFE_MSG_Message_t                Msg; /**< \brief Base message */
     CFE_MSG_CommandSecondaryHeader_t Sec; /**< \brief Secondary header */
+    uint8                            Spare[4]; /**< /brief Padding to end on 64 bit boundary */
 
 } CFE_MSG_CommandHeader_t;