diff --git a/external/json/Makefile b/external/json/Makefile
index ce375cb..7bfac18 100644
--- a/external/json/Makefile
+++ b/external/json/Makefile
@@ -13,7 +13,7 @@
 ##### Build defaults #####
 CC     = cc
 AR     = ar rcu
-CFLAGS = -O2 -Wall -Wno-unused-function -pedantic -fpic -DNDEBUG -I../../lua-5.4
+CFLAGS = -std=c99 -O2 -Wall -Wno-unused-function -pedantic -fpic -DNDEBUG -I../../lua-5.4
 OBJS   = dtoa.o fpconv.o g_fmt.o lua_cjson.o strbuf.o
 
 ##### End customisable sections #####
diff --git a/external/json/lua_cjson.c b/external/json/lua_cjson.c
index fab4b5e..34e456c 100644
--- a/external/json/lua_cjson.c
+++ b/external/json/lua_cjson.c
@@ -227,6 +227,64 @@ static const char *char2escape[256] = {
     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 };
 
+/*
+ * This array is designed for mapping upper and lower case letter
+ * together for a case independent comparison.  The mappings are
+ * based upon ascii character sequences.
+ */
+static const unsigned char charmap[] = {
+	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
+	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
+	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
+	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
+	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
+	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
+	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
+	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
+	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
+	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
+	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
+	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
+	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
+	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
+	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
+	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
+	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
+	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
+	'\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307',
+	'\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317',
+	'\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327',
+	'\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337',
+	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
+	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
+	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
+	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
+};
+
+/* Implementation from OpenBSD */
+int strncasecmp(const char *s1, const char *s2, size_t n)
+{
+	if (n != 0) {
+		const unsigned char *cm = charmap;
+		const unsigned char *us1 = (const unsigned char *)s1;
+		const unsigned char *us2 = (const unsigned char *)s2;
+
+		do {
+			if (cm[*us1] != cm[*us2++])
+				return (cm[*us1] - cm[*--us2]);
+			if (*us1++ == '\0')
+				break;
+		} while (--n != 0);
+	}
+	return (0);
+}
+
 /* ===== CONFIGURATION ===== */
 
 static json_config_t *json_fetch_config(lua_State *l)
@@ -299,7 +357,7 @@ static int json_enum_option(lua_State *l, int optindex, int *setting,
     return 1;
 }
 
-#define streq(s1, s2) (strcmp(s1, s2) == 0)
+#define streq(s1, s2) (strcmp((s1), (s2)) == 0)
 
 #if defined(DISABLE_INVALID_NUMBERS) && !defined(USE_INTERNAL_FPCONV)
 void json_verify_invalid_number_setting(lua_State *l, int *setting)
diff --git a/lua-5.4/Makefile b/lua-5.4/Makefile
index 915af95..7592356 100644
--- a/lua-5.4/Makefile
+++ b/lua-5.4/Makefile
@@ -6,7 +6,7 @@
 # Your platform. See PLATS for possible values.
 PLAT= guess
 
-CC= cc -std=gnu99
+CC= cc -std=c99
 CFLAGS= -O2 -fpic -Wall -Wextra -DLUA_COMPAT_5_3 $(SYSCFLAGS) $(MYCFLAGS)
 LDFLAGS= $(SYSLDFLAGS) $(MYLDFLAGS)
 LIBS= -lm $(SYSLIBS) $(MYLIBS)