diff --git a/fsw/platform_inc/to_lab_sub_table.h b/fsw/platform_inc/to_lab_sub_table.h
index a78384b..e9a71da 100644
--- a/fsw/platform_inc/to_lab_sub_table.h
+++ b/fsw/platform_inc/to_lab_sub_table.h
@@ -26,6 +26,8 @@
 ** Notes:
 **
 *************************************************************************/
+#ifndef to_lab_sub_table_h_
+#define to_lab_sub_table_h_
 
 #include "cfe_msgids.h"
 #include "cfe_platform_cfg.h"
@@ -43,3 +45,5 @@ typedef struct
     TO_LAB_Sub_t Subs[CFE_PLATFORM_SB_MAX_MSG_IDS];
 }
 TO_LAB_Subs_t;
+
+#endif /* to_lab_sub_table_h_ */