diff --git a/telemetry/conf/master.cfg b/telemetry/conf/master.cfg
index cabbdb5..5b3044b 100644
--- a/telemetry/conf/master.cfg
+++ b/telemetry/conf/master.cfg
@@ -9,7 +9,7 @@ debug = False
 version = '0.0.1.trunk'
 commit = None
 
-radio_mtu = 1446          # MAX_PAYLOAD_SIZE, don't change if doubt
+radio_mtu = 1445          # MAX_PAYLOAD_SIZE, don't change if doubt
 mavlink_agg_timeout = 0.1 # aggragate mavlink packets if less than radio_mtu but no longer than 100ms
 tx_sel_delta = 3          # hysteresis for antenna selection, [dB]
 wifi_channel = 165        # radio channel @5825 MHz, range: 5815-5835 MHz, width 20MHz
diff --git a/telemetry/tests/test_proxy.py b/telemetry/tests/test_proxy.py
index c6a7aa7..7f2b436 100644
--- a/telemetry/tests/test_proxy.py
+++ b/telemetry/tests/test_proxy.py
@@ -45,7 +45,7 @@ class SendPacket(DatagramProtocol):
 
 class UDPProxyTestCase(unittest.TestCase):
     def setUp(self):
-        self.p1 = UDPProxyProtocol(agg_max_size=1446, agg_timeout=1, inject_rssi=True)
+        self.p1 = UDPProxyProtocol(agg_max_size=1445, agg_timeout=1, inject_rssi=True)
         self.p2 = UDPProxyProtocol(('127.0.0.1', 14553))
         self.p1.peer = self.p2
         self.p2.peer = self.p1