diff --git a/arch/arm/src/stm32/chip/stm32f20xxx_rcc.h b/arch/arm/src/stm32/chip/stm32f20xxx_rcc.h
index 837094d0114..6dbb7f1d71e 100644
--- a/arch/arm/src/stm32/chip/stm32f20xxx_rcc.h
+++ b/arch/arm/src/stm32/chip/stm32f20xxx_rcc.h
@@ -1,7 +1,7 @@
 /****************************************************************************************************
  * arch/arm/src/stm32/chip/stm32f20xxx_rcc.h
  *
- *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2012, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -357,6 +357,8 @@
 #define RCC_APB1ENR_CAN2EN           (1 << 26) /* Bit 26: CAN 2 clock enable */
 #define RCC_APB1ENR_PWREN            (1 << 28) /* Bit 28: Power interface clock enable */
 #define RCC_APB1ENR_DACEN            (1 << 29) /* Bit 29: DAC interface clock enable */
+#define RCC_APB1ENR_UART7EN          (1 << 30) /* Bit 30: UART7 clock enable */
+#define RCC_APB1ENR_UART8EN          (1 << 31) /* Bit 31: UART8 clock enable */
 
 /* APB2 Peripheral Clock enable register */
 
diff --git a/arch/arm/src/stm32/stm32_serial.c b/arch/arm/src/stm32/stm32_serial.c
index 42973bce158..de499ab086f 100644
--- a/arch/arm/src/stm32/stm32_serial.c
+++ b/arch/arm/src/stm32/stm32_serial.c
@@ -1,7 +1,7 @@
 /****************************************************************************
  * arch/arm/src/stm32/stm32_serial.c
  *
- *   Copyright (C) 2009-2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2009-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -1375,13 +1375,13 @@ static void up_set_apb_clock(struct uart_dev_s *dev, bool on)
 #endif
 #ifdef CONFIG_STM32_UART7
     case STM32_UART7_BASE:
-      rcc_en = RCC_APB1ENR_USART5EN;
+      rcc_en = RCC_APB1ENR_UART7EN;
       regaddr = STM32_RCC_APB1ENR;
       break;
 #endif
 #ifdef CONFIG_STM32_UART8
     case STM32_UART8_BASE:
-      rcc_en = RCC_APB1ENR_USART5EN;
+      rcc_en = RCC_APB1ENR_UART8EN;
       regaddr = STM32_RCC_APB1ENR;
       break;
 #endif