diff --git a/lib/usart.c b/lib/usart.c
index f337430..ca9f827 100644
--- a/lib/usart.c
+++ b/lib/usart.c
@@ -47,7 +47,7 @@ static uint8_t rx_buffer[USART_BUFFER] = {0}; /**< ring buffer for received data
 static volatile uint8_t rx_i = 0; /**< current position of read received data */
 static volatile uint8_t rx_used = 0; /**< how much data has been received and not red */
 static uint8_t tx_buffer[USART_BUFFER] = {0}; /**< ring buffer for data to transmit */
-static volatile uint8_t tx_i = 0; /**< current position if transmitted data */
+static volatile uint8_t tx_i = 0; /**< current position of transmitted data */
 static volatile uint8_t tx_used = 0; /**< how much data needs to be transmitted */
 
 volatile bool usart_received = false;