diff --git a/system_stm32f1xx/system_stm32f1xx.c b/system_stm32f1xx/system_stm32f1xx.c
index dd6c344..b18e9bf 100644
--- a/system_stm32f1xx/system_stm32f1xx.c
+++ b/system_stm32f1xx/system_stm32f1xx.c
@@ -84,7 +84,7 @@
   *
   ******************************************************************************
   */
-#if !defined(ARDUINO)
+#if defined(STM32F105xC)
 
 /** @addtogroup CMSIS
   * @{