diff --git a/drivers/at86rf2xx/at86rf2xx.c b/drivers/at86rf2xx/at86rf2xx.c
index fbd06d80d941c5e823f9df010cd77d89a403324b..a34e802aeeebf9bcbb44947767df84619686e17b 100644
--- a/drivers/at86rf2xx/at86rf2xx.c
+++ b/drivers/at86rf2xx/at86rf2xx.c
@@ -77,7 +77,7 @@ void at86rf2xx_reset(at86rf2xx_t *dev)
     cpuid_get(cpuid);
 
 #if CPUID_LEN > IEEE802154_LONG_ADDRESS_LEN
-    for (int i = IEEE802154_LONG_ADDRESS_LEN; i < CPUID_LEN; i++) {
+    for (unsigned int i = IEEE802154_LONG_ADDRESS_LEN; i < CPUID_LEN; i++) {
         cpuid[i & 0x07] ^= cpuid[i];
     }
 #endif
diff --git a/drivers/at86rf2xx/at86rf2xx_netdev.c b/drivers/at86rf2xx/at86rf2xx_netdev.c
index 7e73624a6f2bb5cb19f1bb2841fee9d2de57d2ed..180d45460617c9208b585e8ebf213775fc68d36d 100644
--- a/drivers/at86rf2xx/at86rf2xx_netdev.c
+++ b/drivers/at86rf2xx/at86rf2xx_netdev.c
@@ -434,8 +434,8 @@ static int _set(netdev2_t *netdev, netopt_t opt, void *val, size_t len)
             }
             else {
                 uint8_t chan = ((uint8_t *)val)[0];
-                if (chan < AT86RF2XX_MIN_CHANNEL ||
-                    chan > AT86RF2XX_MAX_CHANNEL) {
+                if ((chan < AT86RF2XX_MIN_CHANNEL) ||
+                    (chan > AT86RF2XX_MAX_CHANNEL)) {
                     res = -EINVAL;
                     break;
                 }