diff --git a/drivers/include/slipdev.h b/drivers/include/slipdev.h
index 9ad916e258..3ba9c45026 100644
--- a/drivers/include/slipdev.h
+++ b/drivers/include/slipdev.h
@@ -61,7 +61,7 @@ typedef struct {
     netdev_t netdev;                        /**< parent class */
     slipdev_params_t config;                /**< configuration parameters */
     tsrb_t inbuf;                           /**< RX buffer */
-    char rxmem[SLIPDEV_BUFSIZE];            /**< memory used by RX buffer */
+    uint8_t rxmem[SLIPDEV_BUFSIZE];         /**< memory used by RX buffer */
     uint16_t inesc;                         /**< device previously received an escape
                                              *   byte */
 } slipdev_t;
diff --git a/drivers/slipdev/slipdev.c b/drivers/slipdev/slipdev.c
index 821bd46f39..7880008e15 100644
--- a/drivers/slipdev/slipdev.c
+++ b/drivers/slipdev/slipdev.c
@@ -44,7 +44,7 @@ static int _init(netdev_t *netdev)
     DEBUG("slipdev: initializing device %p on UART %i with baudrate %" PRIu32 "\n",
           (void *)dev, dev->config.uart, dev->config.baudrate);
     /* initialize buffers */
-    tsrb_init(&dev->inbuf, (uint8_t *)dev->rxmem, sizeof(dev->rxmem));
+    tsrb_init(&dev->inbuf, dev->rxmem, sizeof(dev->rxmem));
     if (uart_init(dev->config.uart, dev->config.baudrate, _slip_rx_cb,
                   dev) != UART_OK) {
         LOG_ERROR("slipdev: error initializing UART %i with baudrate %" PRIu32 "\n",