diff --git a/atusb/fw/flash.c b/atusb/fw/flash.c
index 136f3da..1f8e59d 100644
--- a/atusb/fw/flash.c
+++ b/atusb/fw/flash.c
@@ -39,7 +39,7 @@ static bool flash_can_write(uint16_t size)
 static void flash_write(const uint8_t *buf, uint16_t size)
 {
 	static uint8_t last;
-        const uint8_t *p;
+	const uint8_t *p;
 
 	for (p = buf; p != buf+size; p++) {
 		if (!(payload & (SPM_PAGESIZE-1))) {
@@ -57,7 +57,7 @@ static void flash_write(const uint8_t *buf, uint16_t size)
 			boot_page_write(payload-SPM_PAGESIZE);
 			boot_spm_busy_wait();
 		}
-        }
+	}
 }
 
 
diff --git a/atusb/fw/spi.c b/atusb/fw/spi.c
index ded5673..ef6bced 100644
--- a/atusb/fw/spi.c
+++ b/atusb/fw/spi.c
@@ -34,9 +34,9 @@ void spi_begin(void)
 uint8_t spi_io(uint8_t v)
 {
 //      while (!(UCSR1A & 1 << UDRE1));
-        UDR1 = v;
-        while (!(UCSR1A & 1 << RXC1));
-        return UDR1;
+	UDR1 = v;
+	while (!(UCSR1A & 1 << RXC1));
+	return UDR1;
 }
 
 
@@ -51,7 +51,7 @@ void spi_recv_block(uint8_t *buf, uint8_t n)
 {
 	if (!n)
 		return;
-        UDR1 = 0;
+	UDR1 = 0;
 	while (--n) {
 		while (!(UCSR1A & 1 << RXC1));
 		*buf++ = UDR1;