diff --git a/Makefile b/Makefile
index d3ccaa7..5ea4901 100644
--- a/Makefile
+++ b/Makefile
@@ -1,12 +1,14 @@
 TOP = $(PWD)
 TOOLCHAIN = $(TOP)/xtensa-lx106-elf
-VENDOR_SDK = 1.3.0
+VENDOR_SDK = 1.4.0
 
 UNZIP = unzip -q -o
 
 VENDOR_SDK_ZIP = $(VENDOR_SDK_ZIP_$(VENDOR_SDK))
 VENDOR_SDK_DIR = $(VENDOR_SDK_DIR_$(VENDOR_SDK))
 
+VENDOR_SDK_ZIP_1.4.0 = esp_iot_sdk_v1.4.0_15_09_18.zip
+VENDOR_SDK_DIR_1.4.0 = esp_iot_sdk_v1.4.0
 VENDOR_SDK_ZIP_1.3.0 = esp_iot_sdk_v1.3.0_15_08_08.zip
 VENDOR_SDK_DIR_1.3.0 = esp_iot_sdk_v1.3.0
 VENDOR_SDK_ZIP_1.2.0 = esp_iot_sdk_v1.2.0_15_07_03.zip
@@ -71,6 +73,10 @@ libcirom: $(TOOLCHAIN)/xtensa-lx106-elf/sysroot/lib/libcirom.a
 
 sdk_patch: .sdk_patch_$(VENDOR_SDK)
 
+.sdk_patch_1.4.0:
+	patch -N -d $(VENDOR_SDK_DIR_1.4.0) -p1 < c_types-c99.patch
+	@touch $@
+
 .sdk_patch_1.3.0:
 	patch -N -d $(VENDOR_SDK_DIR_1.3.0) -p1 < c_types-c99.patch
 	@touch $@
@@ -198,6 +204,9 @@ $(VENDOR_SDK_DIR)/.dir: $(VENDOR_SDK_ZIP)
 	-mv License $(VENDOR_SDK_DIR)
 	touch $@
 
+esp_iot_sdk_v1.4.0_15_09_18.zip:
+	wget --content-disposition "http://bbs.espressif.com/download/file.php?id=838"
+
 esp_iot_sdk_v1.3.0_15_08_08.zip:
 	wget --content-disposition "http://bbs.espressif.com/download/file.php?id=664"