diff --git a/Makefile b/Makefile
index 4e5fa72..587e188 100644
--- a/Makefile
+++ b/Makefile
@@ -56,7 +56,7 @@ XTENSA_TOOLS_ROOT ?= $(abspath ../esp-open-sdk/xtensa-lx106-elf/bin)/
 
 # Base directory of the ESP8266 SDK package, absolute
 # Typically you'll download from Espressif's BBS, http://bbs.espressif.com/viewforum.php?f=5
-SDK_BASE	?= $(abspath ../esp_iot_sdk_v1.5.1)
+SDK_BASE	?= $(abspath ../esp-open-sdk/esp_iot_sdk_v1.5.2)
 
 # Esptool.py path and port, only used for 1-time serial flashing
 # Typically you'll use https://github.com/themadinventor/esptool
@@ -213,7 +213,7 @@ EXTRA_INCDIR 	= include .
 LIBS = c gcc hal phy pp net80211 wpa main lwip crypto
 
 # compiler flags using during compilation of source files
-CFLAGS	+= -Os -ggdb -std=c99 -Werror -Wpointer-arith -Wundef -Wall -Wl,-EL -fno-inline-functions \
+CFLAGS	+= -Os -ggdb -std=c99 -I$(SDK_BASE)/include -Wpointer-arith -Wundef -Wall -Wl,-EL -fno-inline-functions \
 		-nostdlib -mlongcalls -mtext-section-literals -ffunction-sections -fdata-sections \
 		-D__ets__ -DICACHE_FLASH -D_STDINT_H -Wno-address -DFIRMWARE_SIZE=$(ESP_FLASH_MAX) \
 		-DMCU_RESET_PIN=$(MCU_RESET_PIN) -DMCU_ISP_PIN=$(MCU_ISP_PIN) \