diff --git a/TODO.md b/TODO.md
index 5e17012..204b22e 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,7 +1,6 @@
 # WifiControlSensor
 * MQTT Watch GPIO value using interuption
 * Configure BMP180 altitude in EEPROM thanks to web interface
-* Enable LIGHT_SLEEP_T wifi sleep type
 * Make mqtt optionnal
 * Make web interface optionnal
 
diff --git a/WifiControlSensor/WifiControlSensor.ino b/WifiControlSensor/WifiControlSensor.ino
index ae149eb..f8f9a91 100644
--- a/WifiControlSensor/WifiControlSensor.ino
+++ b/WifiControlSensor/WifiControlSensor.ino
@@ -35,14 +35,18 @@
 #include <EEPROM.h>
 #include <ArduinoOTA.h>
 #include <errno.h>
+
 #include "config.h"
 
 #include "debug_sketch.h"
 #include "BMP180.h"
-
 #include "Adafruit_MQTT.h"
 #include "Adafruit_MQTT_Client.h"
 
+extern "C" {
+#include <user_interface.h>
+}
+
 #define CONFIG_EEPROM_SIZE 256
 char eeprom[CONFIG_EEPROM_SIZE];
 
@@ -218,6 +222,9 @@ void setup() {
       SKETCH_DEBUG_PRINTLN("BMP180 init success");
     WebSetupServer(mode);
   }
+#ifdef CONFIG_ENABLE_LIGHT_SLEEP
+  wifi_set_sleep_type(LIGHT_SLEEP_T);
+#endif
 }
 
 uint nbCycle = 0;
diff --git a/WifiControlSensor/config_device.h b/WifiControlSensor/config_device.h
index d3bde77..1fd9978 100644
--- a/WifiControlSensor/config_device.h
+++ b/WifiControlSensor/config_device.h
@@ -12,6 +12,9 @@
 #define CONFIG_BMP180_SDA 12
 #define CONFIG_BMP180_SCL 14
 
+// Enable light sleep to save some power (http://bbs.espressif.com/viewtopic.php?f=6&t=133&p=485&hilit=sleep+modem#p485)
+//#define CONFIG_ENABLE_LIGHT_SLEEP
+
 /* DEFAULT VALUE ALSO DEFINED IN CONFIG.H */
 
 // Time to sleep between 2 webserver request (increase it reduce battery usage but increase latency)