diff --git a/arch/arm/src/lpc43xx/lpc43_uart.c b/arch/arm/src/lpc43xx/lpc43_uart.c
index f030546953c..4491830f97e 100644
--- a/arch/arm/src/lpc43xx/lpc43_uart.c
+++ b/arch/arm/src/lpc43xx/lpc43_uart.c
@@ -275,7 +275,7 @@ void lpc43_usart0_reset(void)
 #endif
 
 #ifdef CONFIG_LPC43_UART1
-EXTERN void lpc43_uart1_reset(void)
+void lpc43_uart1_reset(void)
 {
   putreg32(RGU_CTRL1_UART1_RST, LPC43_RGU_CTRL1);
 }