diff --git a/examples/serial_echo_irq.rs b/examples/serial_echo_irq.rs
index 8a382e7..8b39908 100644
--- a/examples/serial_echo_irq.rs
+++ b/examples/serial_echo_irq.rs
@@ -61,7 +61,7 @@ fn main() -> ! {
         // initialize global serial
         *SER_PORT.borrow(cs).borrow_mut() =
             Some(Serial::usart1(dp.USART1, (tx, rx), 9_600.bps(), &mut rcc));
-        
+
         if let Some(ser) = SER_PORT.borrow(cs).borrow_mut().as_mut() {
             ser.listen(hal::serial::Event::Rxne); // trigger the USART1 interrupt when bytes are available (receive buffer not empty)
         }