diff --git a/Makefile b/Makefile
index 1c8d719..96e2d4b 100644
--- a/Makefile
+++ b/Makefile
@@ -70,7 +70,7 @@ HEADER_LIST = $$(find * -name '*.h')
 
 FLAGS = -I. -Werror -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare -Wformat=2
 
-compiler_c = $(CC) $(FLAGS) $(CFLAGS)
+compiler_c = $(CC) $(FLAGS) $(CFLAGS) -std=gnu99
 compiler_c++ = $(CXX) $(FLAGS) $(CXXFLAGS)
 compile = $(compiler_$1) -include "$$header" -c -x $1 /dev/null -o /dev/null
 
diff --git a/examples/Makefile b/examples/Makefile
index b5541d3..2a18ac9 100644
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -1,7 +1,7 @@
 PREFIX ?= /usr/local
 WARN = -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare
 CPPFLAGS = -I. -I.. -I../..
-CFLAGS := $(WARN) -O2 -g $(CFLAGS)
+CFLAGS := $(WARN) -O2 -g -std=gnu99 $(CFLAGS)
 OBJ = dvb_print_si dvb_gen_si dvb_ecmg dvb_ecmg_test mpeg_print_pcr rtp_check_seqnum mpeg_restamp
 
 ifeq "$(shell uname -s)" "Linux"
diff --git a/ietf/rtp2435.h b/ietf/rtp2435.h
index 11b5d8b..23e8343 100644
--- a/ietf/rtp2435.h
+++ b/ietf/rtp2435.h
@@ -31,6 +31,10 @@
 #ifndef __BITSTREAM_IETF_RTP2435_H__
 #define __BITSTREAM_IETF_RTP2435_H__
 
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+
 #ifdef __cplusplus
 extern "C"
 {
@@ -125,7 +129,7 @@ static inline uint8_t *rtp2435_restart(uint8_t *header)
 static inline uint8_t *rtp2435_quantization_table(uint8_t *header)
 {
     uint8_t q = rtp2435_get_q(header);
-    if (128 <= q && q <= 255) {
+    if (128 <= q) {
         uint8_t *p;
         if ((p = rtp2435_restart(header)))
             return p + RTP_2435_RESTART_HEADER_SIZE;