diff --git a/src/platforms/common/aux_serial.c b/src/platforms/common/aux_serial.c
index c27675f..8f2a1d4 100644
--- a/src/platforms/common/aux_serial.c
+++ b/src/platforms/common/aux_serial.c
@@ -38,9 +38,9 @@
 #include "aux_serial.h"
 
 /* Fifo in pointer, writes assumed to be atomic, should be only incremented within RX ISR */
-uint8_t buf_rx_in;
+uint8_t aux_serial_receive_write_index;
 /* Fifo out pointer, writes assumed to be atomic, should be only incremented outside RX ISR */
-uint8_t buf_rx_out;
+uint8_t aux_serial_receive_read_index;
 
 #if defined(STM32F0) || defined(STM32F1) || defined(STM32F3) || defined(STM32F4)
 static char aux_serial_transmit_buffer[2U][AUX_UART_BUFFER_SIZE];
@@ -442,13 +442,13 @@ void USBUART_ISR(void)
 		/* If the next increment of rx_in would put it at the same point
 		* as rx_out, the FIFO is considered full.
 		*/
-		if (((buf_rx_in + 1) % AUX_UART_BUFFER_SIZE) != buf_rx_out) {
+		if (((aux_serial_receive_write_index + 1) % AUX_UART_BUFFER_SIZE) != aux_serial_receive_read_index) {
 			/* insert into FIFO */
-			buf_rx[buf_rx_in++] = c;
+			buf_rx[aux_serial_receive_write_index++] = c;
 
 			/* wrap out pointer */
-			if (buf_rx_in >= AUX_UART_BUFFER_SIZE)
-				buf_rx_in = 0;
+			if (aux_serial_receive_write_index >= AUX_UART_BUFFER_SIZE)
+				aux_serial_receive_write_index = 0;
 		} else
 			flush = true;
 	}
@@ -456,16 +456,16 @@ void USBUART_ISR(void)
 	if (flush) {
 		/* forcibly empty fifo if no USB endpoint */
 		if (usb_get_config() != 1) {
-			buf_rx_out = buf_rx_in;
+			aux_serial_receive_read_index = aux_serial_receive_write_index;
 			return;
 		}
 
 		char packet_buf[CDCACM_PACKET_SIZE];
 		uint8_t packet_size = 0;
-		uint8_t buf_out = buf_rx_out;
+		uint8_t buf_out = aux_serial_receive_read_index;
 
 		/* copy from uart FIFO into local usb packet buffer */
-		while (buf_rx_in != buf_out && packet_size < CDCACM_PACKET_SIZE) {
+		while (aux_serial_receive_write_index != buf_out && packet_size < CDCACM_PACKET_SIZE) {
 			packet_buf[packet_size++] = buf_rx[buf_out++];
 
 			/* wrap out pointer */
@@ -474,9 +474,9 @@ void USBUART_ISR(void)
 		}
 
 		/* advance fifo out pointer by amount written */
-		buf_rx_out += usbd_ep_write_packet(usbdev,
+		aux_serial_receive_read_index += usbd_ep_write_packet(usbdev,
 				CDCACM_UART_ENDPOINT, packet_buf, packet_size);
-		buf_rx_out %= AUX_UART_BUFFER_SIZE;
+		aux_serial_receive_read_index %= AUX_UART_BUFFER_SIZE;
 	}
 }
 #endif
diff --git a/src/platforms/common/usb_serial.c b/src/platforms/common/usb_serial.c
index 08789cc..c1e304f 100644
--- a/src/platforms/common/usb_serial.c
+++ b/src/platforms/common/usb_serial.c
@@ -240,12 +240,12 @@ static void debug_uart_send_rx_packet(void)
 {
 	aux_serial_receive_complete = false;
 	/* Calculate writing position in the FIFO */
-	const uint32_t buf_rx_in =
+	const uint32_t aux_serial_receive_write_index =
 		(AUX_UART_BUFFER_SIZE - dma_get_number_of_data(USBUSART_DMA_BUS, USBUSART_DMA_RX_CHAN)) % AUX_UART_BUFFER_SIZE;
 
 	/* Forcibly empty fifo if no USB endpoint.
 	 * If fifo empty, nothing further to do. */
-	if (usb_get_config() != 1 || (buf_rx_in == buf_rx_out
+	if (usb_get_config() != 1 || (aux_serial_receive_write_index == aux_serial_receive_read_index
 #ifdef ENABLE_DEBUG
 		&& usb_dbg_in == usb_dbg_out
 #endif
@@ -254,7 +254,7 @@ static void debug_uart_send_rx_packet(void)
 #ifdef ENABLE_DEBUG
 		usb_dbg_out = usb_dbg_in;
 #endif
-		buf_rx_out = buf_rx_in;
+		aux_serial_receive_read_index = aux_serial_receive_write_index;
 		/* Turn off LED */
 		usbuart_set_led_state(RX_LED_ACT, false);
 		aux_serial_receive_complete = true;
@@ -280,11 +280,11 @@ static void debug_uart_send_rx_packet(void)
 #endif
 
 		/* Copy data from uart RX FIFO into local usb packet buffer */
-		packet_size = copy_from_fifo(packet_buf, buf_rx, buf_rx_out, buf_rx_in, CDCACM_PACKET_SIZE - 1, AUX_UART_BUFFER_SIZE);
+		packet_size = copy_from_fifo(packet_buf, buf_rx, aux_serial_receive_read_index, aux_serial_receive_write_index, CDCACM_PACKET_SIZE - 1, AUX_UART_BUFFER_SIZE);
 
 		/* Advance fifo out pointer by amount written */
 		const uint16_t written = usbd_ep_write_packet(usbdev, CDCACM_UART_ENDPOINT, packet_buf, packet_size);
-		buf_rx_out = (buf_rx_out + written) % AUX_UART_BUFFER_SIZE;
+		aux_serial_receive_read_index = (aux_serial_receive_read_index + written) % AUX_UART_BUFFER_SIZE;
 	}
 }
 
diff --git a/src/platforms/common/usbuart.h b/src/platforms/common/usbuart.h
index ce22761..6c4345e 100644
--- a/src/platforms/common/usbuart.h
+++ b/src/platforms/common/usbuart.h
@@ -58,6 +58,6 @@ extern uint8_t usb_dbg_out;
 extern char buf_rx[AUX_UART_BUFFER_SIZE];
 #endif
 
-extern uint8_t buf_rx_out;
+extern uint8_t aux_serial_receive_read_index;
 
 #endif