diff --git a/kernel/uart.c b/kernel/uart.c
index 3c1dc34..f75fb3c 100644
--- a/kernel/uart.c
+++ b/kernel/uart.c
@@ -43,7 +43,7 @@ struct spinlock uart_tx_lock;
 #define UART_TX_BUF_SIZE 32
 char uart_tx_buf[UART_TX_BUF_SIZE];
 uint64 uart_tx_w; // write next to uart_tx_buf[uart_tx_w % UART_TX_BUF_SIZE]
-uint64 uart_tx_r; // read next from uart_tx_buf[uar_tx_r % UART_TX_BUF_SIZE]
+uint64 uart_tx_r; // read next from uart_tx_buf[uart_tx_r % UART_TX_BUF_SIZE]
 
 extern volatile int panicked; // from printf.c