https://github.com/Yubico/libu2f-server/commit/f7c4983b31909299c47bf9b2627c84b6bfe225de
--- u2f-server/core.c.orig	2017-12-18 03:52:12.000000000 -0800
+++ u2f-server/core.c	2021-08-13 22:45:10.000000000 -0700
@@ -44,6 +44,19 @@
 #define u2fs_json_object_object_get(obj, key, value) (value = json_object_object_get(obj, key)) == NULL ? (json_bool)FALSE : (json_bool)TRUE
 #endif
 
+/* json-c 0.13.99 does not define TRUE/FALSE anymore
+ * the json-c maintainers replaced them with pure 1/0
+ * https://github.com/json-c/json-c/commit/0992aac61f8b
+ */
+#if defined JSON_C_VERSION_NUM && JSON_C_VERSION_NUM >= ((13 << 8) | 99)
+#ifndef FALSE
+#define FALSE 0
+#endif
+#ifndef TRUE
+#define TRUE  1
+#endif
+#endif
+
 static u2fs_rc encode_b64u(const char *data, size_t data_len, char *output)
 {
   base64_encodestate b64;