diff --git a/global.h b/global.h
index 92c2645..c5120fc 100644
--- a/global.h
+++ b/global.h
@@ -43,7 +43,7 @@
 /** get interrupt service routine for timer base on TIM */
 #define TIM_ISR(x) CAT3(tim,x,_isr)
 /** get external interrupt based on pin identifier */
-#define EXTI(x) CAT2(EXT,x)
+#define EXTI(x) CAT2(EXTI,x)
 /** get NVIC IRQ for external interrupt base on external interrupt/pin */
 #define NVIC_EXTI_IRQ(x) CAT3(NVIC_EXTI,x,_IRQ)
 #define NVIC_EXTI5_IRQ NVIC_EXTI9_5_IRQ /**< IRQ for line 9 to 5 for pin 5 */