diff --git a/lib/uart.c b/lib/uart.c
index 5f70af9..d602b27 100644
--- a/lib/uart.c
+++ b/lib/uart.c
@@ -15,7 +15,7 @@
 /** library for UART communication (code)
  *  @file uart.c
  *  @author King Kévin <kingkevin@cuvoodoo.info>
- *  @date 2016-2017
+ *  @date 2016-2018
  *  @note peripherals used: USART @ref uart
  */
 
@@ -92,7 +92,7 @@ void uart_putchar_nonblocking(char c)
 {
 	while (tx_used>=LENGTH(tx_buffer)) { // idle until buffer has some space
 		usart_enable_tx_interrupt(USART(UART_ID)); // enable transmit interrupt
-		__WFI(); // sleep until something happened
+		// don't go to sleep since this might prevent an interrupt
 	}
 	usart_disable_tx_interrupt(USART(UART_ID)); // disable transmit interrupt to prevent index corruption
 	tx_buffer[(tx_i+tx_used)%LENGTH(tx_buffer)] = c; // put character in buffer