diff --git a/include/PinMapping.h b/include/PinMapping.h
index 9539b824..7f7324f8 100644
--- a/include/PinMapping.h
+++ b/include/PinMapping.h
@@ -50,7 +50,7 @@ struct PinMapping_t {
     uint8_t display_cs;
     uint8_t display_reset;
 
-    int8_t led[PINMAPPING_LED_COUNT];
+    gpio_num_t led[PINMAPPING_LED_COUNT];
 };
 
 class PinMappingClass {
diff --git a/platformio.ini b/platformio.ini
index 4eec14f5..520cc6ac 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -233,8 +233,8 @@ build_flags = ${env.build_flags}
     -DHOYMILES_PIN_IRQ=47
     -DHOYMILES_PIN_CE=38
     -DHOYMILES_PIN_CS=37
-    -DLED0=17
-    -DLED1=18
+    -DLED0=GPIO_NUM_17
+    -DLED1=GPIO_NUM_18
     -DARDUINO_USB_MODE=1
     -DARDUINO_USB_CDC_ON_BOOT=1
 
@@ -250,8 +250,8 @@ build_flags = ${env.build_flags}
     -DHOYMILES_PIN_IRQ=47
     -DHOYMILES_PIN_CE=38
     -DHOYMILES_PIN_CS=37
-    -DLED0=17
-    -DLED1=18
+    -DLED0=GPIO_NUM_17
+    -DLED1=GPIO_NUM_18
     -DCMT_CLK=6
     -DCMT_CS=4
     -DCMT_FCS=21
@@ -273,8 +273,8 @@ build_flags = ${env.build_flags}
     -DHOYMILES_PIN_IRQ=47
     -DHOYMILES_PIN_CE=38
     -DHOYMILES_PIN_CS=37
-    -DLED0=17
-    -DLED1=18
+    -DLED0=GPIO_NUM_17
+    -DLED1=GPIO_NUM_18
     -DCMT_CLK=6
     -DCMT_CS=4
     -DCMT_FCS=21
diff --git a/src/Led_Single.cpp b/src/Led_Single.cpp
index 40320b1f..07b1eeaf 100644
--- a/src/Led_Single.cpp
+++ b/src/Led_Single.cpp
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * Copyright (C) 2023-2024 Thomas Basler and others
+ * Copyright (C) 2023-2025 Thomas Basler and others
  */
 #include "Led_Single.h"
 #include "Configuration.h"
@@ -53,7 +53,7 @@ void LedSingleClass::init(Scheduler& scheduler)
     const auto& pin = PinMapping.get();
     for (uint8_t i = 0; i < PINMAPPING_LED_COUNT; i++) {
 
-        if (pin.led[i] >= 0) {
+        if (pin.led[i] > GPIO_NUM_NC) {
             pinMode(pin.led[i], OUTPUT);
             setLed(i, false);
             ledActive = true;
@@ -131,7 +131,7 @@ void LedSingleClass::setLed(const uint8_t ledNo, const bool ledState)
     const auto& pin = PinMapping.get();
     const auto& config = Configuration.get();
 
-    if (pin.led[ledNo] < 0) {
+    if (pin.led[ledNo] == GPIO_NUM_NC) {
         return;
     }
 
diff --git a/src/PinMapping.cpp b/src/PinMapping.cpp
index b0ba6647..0c072604 100644
--- a/src/PinMapping.cpp
+++ b/src/PinMapping.cpp
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * Copyright (C) 2022 - 2023 Thomas Basler and others
+ * Copyright (C) 2022 - 2025 Thomas Basler and others
  */
 #include "PinMapping.h"
 #include "MessageOutput.h"
@@ -30,11 +30,11 @@
 #endif
 
 #ifndef LED0
-#define LED0 -1
+#define LED0 GPIO_NUM_NC
 #endif
 
 #ifndef LED1
-#define LED1 -1
+#define LED1 GPIO_NUM_NC
 #endif
 
 #ifndef HOYMILES_PIN_SCLK