diff --git a/Makefile b/Makefile
index e5d5f7e..7f3e236 100644
--- a/Makefile
+++ b/Makefile
@@ -72,7 +72,7 @@ DEFS += -DSTM32F1 -D$(BOARD)
 
 # C flags
 CFLAGS += -Os -g
-CFLAGS += -Wall -Werror -Wundef -Wextra -Wshadow -Wimplicit-function-declaration -Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes
+CFLAGS += -std=c99 -Wpedantic -Wall -Werror -Wundef -Wextra -Wshadow -Wimplicit-function-declaration -Wredundant-decls -Wmissing-prototypes -Wstrict-prototypes
 CFLAGS += -fno-common -ffunction-sections -fdata-sections
 CFLAGS += -I. -I$(INCLUDE_DIR) $(patsubst %,-I%,$(LIB))
 CFLAGS += $(DEFS)
diff --git a/lib/led_ws2812b.c b/lib/led_ws2812b.c
index 8b0c904..6911112 100644
--- a/lib/led_ws2812b.c
+++ b/lib/led_ws2812b.c
@@ -57,7 +57,7 @@
  * the second SPI bit determines if the WS2812b bit is a 0 or 1
  * the third SPI bit is the last part of the  WS2812b bit frame, which is always low
  * only the first 24 bits (3*8) are used */
-#define WS2812B_SPI_TEMPLATE 0b10010010010010010010010000000000
+#define WS2812B_SPI_TEMPLATE 0x92492400 //0b10010010010010010010010000000000
 
 uint8_t ws2812b_data[WS2812B_LEDS*3*3+40*3/8] = {0};  // SPI encode data to be shifted out for WS2812b + the 50us reset
 static volatile bool transmit_flag = false; // is transmission ongoing
@@ -81,7 +81,7 @@ void ws2812b_set_rgb(uint16_t led, uint8_t red, uint8_t green, uint8_t blue)
 	for (uint8_t color=0; color<LENGTH(colors); color++) {
 		uint32_t bits_color = WS2812B_SPI_TEMPLATE; // template to encode the bits in
 		for (uint8_t bit=0; bit<8; bit++) {
-			bits_color |= ((colors[color]>>bit)&0b1)<<(bit*3+9); // encode the data bits in the pattern
+			bits_color |= ((colors[color]>>bit)&0x1)<<(bit*3+9); // encode the data bits in the pattern
 		}
 		// store pattern
 		ws2812b_data[led*3*3+color*3+0] = (bits_color>>24);
diff --git a/lib/rtc_ds1307.c b/lib/rtc_ds1307.c
index b304256..da4e148 100644
--- a/lib/rtc_ds1307.c
+++ b/lib/rtc_ds1307.c
@@ -51,7 +51,7 @@
 #define I2C_PIN_SCL GPIO_I2C1_SCL
 /** @} */
 /** DS1307 I2C address (fixed) */
-#define I2C_ADDR 0b1101000
+#define I2C_ADDR 0x68 //0b1101000
 
 void rtc_setup(void)
 {