diff --git a/include/libopencm3/sam3x/usart.h b/include/libopencm3/sam3x/usart.h
index bf5e4bf9..ac7db1d5 100644
--- a/include/libopencm3/sam3x/usart.h
+++ b/include/libopencm3/sam3x/usart.h
@@ -210,6 +210,8 @@ void usart_wait_send_ready(u32 usart);
 void usart_wait_recv_ready(u32 usart);
 void usart_send_blocking(u32 usart, u16 data);
 u16 usart_recv_blocking(u32 usart);
+void usart_enable_rx_interrupt(u32 usart);
+void usart_disable_rx_interrupt(u32 usart);
 
 #endif
 
diff --git a/lib/sam3x/usart.c b/lib/sam3x/usart.c
index 012a07e0..4d1114f1 100644
--- a/lib/sam3x/usart.c
+++ b/lib/sam3x/usart.c
@@ -97,3 +97,13 @@ u16 usart_recv_blocking(u32 usart)
 	return usart_recv(usart);
 }
 
+void usart_enable_rx_interrupt(u32 usart)
+{
+	USART_IER(usart) = USART_CSR_RXRDY;
+}
+
+void usart_disable_rx_interrupt(u32 usart)
+{
+	USART_IDR(usart) = USART_CSR_RXRDY;
+}
+