diff --git a/ports/stm32/mpu.h b/ports/stm32/mpu.h
index 2541d86bfb..1efe93a68b 100644
--- a/ports/stm32/mpu.h
+++ b/ports/stm32/mpu.h
@@ -26,7 +26,7 @@
 #ifndef MICROPY_INCLUDED_STM32_MPU_H
 #define MICROPY_INCLUDED_STM32_MPU_H
 
-#if defined(STM32F7) || defined(STM32H7)
+#if defined(STM32F7) || defined(STM32H7) || defined(MICROPY_HW_ETH_MDC)
 
 #define MPU_REGION_ETH      (MPU_REGION_NUMBER0)
 #define MPU_REGION_QSPI1    (MPU_REGION_NUMBER1)