diff --git a/code/src/config/hardware.h b/code/src/config/hardware.h
index 1c0e173f..1a4ef2af 100644
--- a/code/src/config/hardware.h
+++ b/code/src/config/hardware.h
@@ -21,6 +21,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             13
+    #define LED_PIN_INVERSE     0
 
 #elif defined(SONOFF_TH)
 
@@ -29,6 +30,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             13
+    #define LED_PIN_INVERSE     0
 
 #elif defined(SONOFF_POW)
 
@@ -37,6 +39,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             15
+    #define LED_PIN_INVERSE     1
     #define ENABLE_POW          1
 
 #elif defined(SLAMPHER)
@@ -46,6 +49,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             13
+    #define LED_PIN_INVERSE     0
 
 #elif defined(S20)
 
@@ -54,6 +58,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             13
+    #define LED_PIN_INVERSE     0
 
 // -----------------------------------------------------------------------------
 // ESPurna board (still beta)
@@ -66,6 +71,7 @@
     #define BUTTON_PIN          0
     #define RELAY_PIN           12
     #define LED_PIN             13
+    #define LED_PIN_INVERSE     0
 
 // -----------------------------------------------------------------------------
 // Unknown hardware
diff --git a/code/src/main.ino b/code/src/main.ino
index b8b6a066..b8282859 100644
--- a/code/src/main.ino
+++ b/code/src/main.ino
@@ -46,7 +46,7 @@ void blink(unsigned long delayOff, unsigned long delayOn) {
     static bool status = HIGH;
     if (next < millis()) {
         status = !status;
-        digitalWrite(LED_PIN, status);
+        digitalWrite(LED_PIN, LED_PIN_INVERSE ? !status : status);
         next += ((status) ? delayOff : delayOn);
     }
 }