diff --git a/firmware/src_simtrace/mode_cardemu.c b/firmware/src_simtrace/mode_cardemu.c
index 9ee31ca7..10b5c4c3 100644
--- a/firmware/src_simtrace/mode_cardemu.c
+++ b/firmware/src_simtrace/mode_cardemu.c
@@ -106,16 +106,16 @@ void usart_irq_rx(uint8_t uart)
 #endif
 	csr = usart->US_CSR;
 
-	if (csr & US_CSR_TXRDY) {
-		if (card_emu_tx_byte(ch) == 0)
-			USART_DisableIt(usart, US_IER_TXRDY);
-	}
-
 	if (csr & US_CSR_RXRDY) {
         	byte = (usart->US_RHR) & 0xFF;
 		rbuf_write(&ch1_rb, byte);
 	}
 
+	if (csr & US_CSR_TXRDY) {
+		if (card_emu_tx_byte(ch) == 0)
+			USART_DisableIt(usart, US_IER_TXRDY);
+	}
+
 	if (csr & (US_CSR_OVRE|US_CSR_FRAME|US_CSR_PARE|
 		   US_CSR_TIMEOUT|US_CSR_NACK|(1<<10))) {
 		usart->US_CR = US_CR_RSTSTA | US_CR_RSTIT | US_CR_RSTNACK;