diff --git a/src/TypeDef.h b/src/TypeDef.h
index 69ea2fc2..6236b2be 100644
--- a/src/TypeDef.h
+++ b/src/TypeDef.h
@@ -77,7 +77,7 @@
 /*!
   \brief Alias for unused pin, if not supplied by the Arduino core.
 */
-#ifndef NC
+#if !(defined(NC) || defined(ARDUINO_ARCH_STM32))
 #define NC                                            (-1)
 #endif