diff --git a/include/update_fw.h b/include/update_fw.h
index 727a3012f5..e454f129bd 100644
--- a/include/update_fw.h
+++ b/include/update_fw.h
@@ -8,6 +8,7 @@
 
 #include <stddef.h>
 
+#include "compile_time_macros.h"
 
 /*
  * This file contains structures used to facilitate EC firmware updates
@@ -217,6 +218,14 @@ struct touchpad_info {
 	} elan;
 } __packed;
 
+/*
+ * The response message must not exceed 64 bytes.
+ * And our protocol has a 14 bytes header.
+ * So the size of `struct touchpad_info` must be less
+ * than or equal to 50 bytes
+ */
+BUILD_ASSERT(sizeof(struct touchpad_info) <= 50);
+
 void fw_update_command_handler(void *body,
 			       size_t cmd_size,
 			       size_t *response_size);