diff --git a/tools/bootconfig/main.c b/tools/bootconfig/main.c
index 17d971d..df05340 100644
--- a/tools/bootconfig/main.c
+++ b/tools/bootconfig/main.c
@@ -495,7 +495,8 @@ static int apply_xbc(const char *path, const char *xbc_path)
 	footer.size = htole32(size);
 	footer.csum = htole32(csum);
 	memcpy(footer.magic, BOOTCONFIG_MAGIC, BOOTCONFIG_MAGIC_LEN);
-	static_assert(sizeof(footer) == BOOTCONFIG_FOOTER_SIZE);
+	static_assert(sizeof(footer) == BOOTCONFIG_FOOTER_SIZE,
+		      "bootconfig footer size mismatch");
 	memcpy(data + size, &footer, BOOTCONFIG_FOOTER_SIZE);
 
 	total_size = size + BOOTCONFIG_FOOTER_SIZE;