diff --git a/src/bus/usart.c b/src/bus/usart.c
index 6f579ee..7f15677 100644
--- a/src/bus/usart.c
+++ b/src/bus/usart.c
@@ -25,11 +25,11 @@ int USART_Init(void)
 	txhead = 0;
 	txtail = 0;
 
-	UCSRB = BIT(RXCIE); // Handle RXC interrupts
-	UCSRB |= BIT(RXEN) | BIT(TXEN); // Enable RX and TX circuitry
-	UCSRC = BIT(URSEL) | BIT(UCSZ0) | BIT(UCSZ1); // Using 8-bit chars
-	UBRRH = (USART_BAUD_PRESCALE >> 8); // Set baud rate upper byte
-	UBRRL = USART_BAUD_PRESCALE; // Set baud rate lower byte
+	UCSR0B = BIT(RXCIE0); // Handle RXC interrupts
+	UCSR0B |= BIT(RXEN0) | BIT(TXEN0); // Enable RX and TX circuitry
+	UCSR0C = BIT(USBS0) | BIT(UCSZ00) | BIT(UCSZ01); // 8-bit data, 2-bit stop
+	UBRR0H = (USART_BAUD_PRESCALE >> 8); // Set baud rate upper byte
+	UBRR0L = USART_BAUD_PRESCALE; // Set baud rate lower byte
 
 	return 0;
 }
@@ -57,16 +57,16 @@ void USART_Putc(char ch)
 	txhead = head;
 
 	// Enable interrupt
-	UCSRB |= BIT(UDRIE);
+	UCSR0B |= BIT(UDRIE0);
 }
 
 // INT: Rx complete
-ISR(USART_RXC_vect)
+ISR(USART0_RX_vect)
 {
 	short head;
 	byte data;
 
-	data = UDR; // Next byte ready
+	data = UDR0; // Next byte ready
 
 	// Wrap around if end of buffer reached
 	head = (rxhead + 1) & USART_RXBUF_MASK;
@@ -80,7 +80,7 @@ ISR(USART_RXC_vect)
 }
 
 // INT: Data register empty
-ISR(USART_UDRE_vect)
+ISR(USART0_UDRE_vect)
 {
 	short tail;
 
@@ -88,10 +88,10 @@ ISR(USART_UDRE_vect)
 	if (txhead != txtail) {
 		// Write next byte to data register
 		tail = (txtail + 1) & USART_TXBUF_MASK;
-		UDR = txbuf[tail];
+		UDR0 = txbuf[tail];
 		txtail = tail;
 	} else {
 		// Disable interrupt
-		UCSRB &= ~BIT(UDRIE);
+		UCSR0B &= ~BIT(UDRIE0);
 	}
 }