diff --git a/radio/src/bluetooth.cpp b/radio/src/bluetooth.cpp
index be35693c7..11576c9be 100644
--- a/radio/src/bluetooth.cpp
+++ b/radio/src/bluetooth.cpp
@@ -217,11 +217,11 @@ void Bluetooth::processTrainerByte(uint8_t data)
 
   if (bufferIndex >= BLUETOOTH_PACKET_SIZE) {
     uint8_t crc = 0x00;
-    for (int i=0; i<13; i++) {
+    for (int i=0; i<(BLUETOOTH_PACKET_SIZE-1); i++) {
       crc ^= buffer[i];
     }
-    if (crc == buffer[13]) {
-      if (buffer[0] == 0x80) {
+    if (crc == buffer[BLUETOOTH_PACKET_SIZE-1]) {
+      if (buffer[0] == TRAINER_FRAME) {
         processTrainerFrame(buffer);
       }
     }
@@ -251,7 +251,7 @@ void Bluetooth::sendTrainer()
   crc = 0x00;
 
   buffer[bufferIndex++] = START_STOP; // start byte
-  pushByte(0x80); // trainer frame type?
+  pushByte(TRAINER_FRAME);
   for (int channel=0; channel<lastCh; channel+=2, cur+=3) {
     uint16_t channelValue1 = PPM_CH_CENTER(channel) + limit((int16_t)-PPM_range, channelOutputs[channel], (int16_t)PPM_range) / 2;
     uint16_t channelValue2 = PPM_CH_CENTER(channel+1) + limit((int16_t)-PPM_range, channelOutputs[channel+1], (int16_t)PPM_range) / 2;
diff --git a/radio/src/telemetry/frsky.h b/radio/src/telemetry/frsky.h
index 8621869c6..1bd899605 100644
--- a/radio/src/telemetry/frsky.h
+++ b/radio/src/telemetry/frsky.h
@@ -259,9 +259,10 @@ inline uint8_t TELEMETRY_RSSI()
   return telemetryData.rssi.value();
 }
 
-constexpr uint8_t START_STOP = 0x7E;
-constexpr uint8_t BYTE_STUFF = 0x7D;
-constexpr uint8_t STUFF_MASK = 0x20;
+constexpr uint8_t START_STOP    = 0x7E;
+constexpr uint8_t BYTE_STUFF    = 0x7D;
+constexpr uint8_t STUFF_MASK    = 0x20;
+constexpr uint8_t TRAINER_FRAME = 0x80;
 
 typedef enum {
   TS_IDLE = 0,  // waiting for 0x5e frame marker