diff --git a/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp b/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
index 965ae0daf..9cc558b51 100644
--- a/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
+++ b/radio/src/targets/common/arm/stm32/aux_serial_driver.cpp
@@ -21,10 +21,6 @@
 #include "opentx.h"
 #include "targets/horus/board.h"
 
-#if defined(SBUS)
-extern Fifo<uint8_t, 32> trainerSbusFifo;
-#endif
-
 #if defined(AUX_SERIAL)
 uint8_t auxSerialMode = UART_MODE_COUNT;  // Prevent debug output before port is setup
 Fifo<uint8_t, 512> auxSerialTxFifo;
@@ -416,4 +412,4 @@ extern "C" void AUX2_SERIAL_USART_IRQHandler(void)
   }
 }
 #endif // SIMU
-#endif // AUX2_SERIAL
\ No newline at end of file
+#endif // AUX2_SERIAL
diff --git a/radio/src/targets/horus/trainer_driver.cpp b/radio/src/targets/horus/trainer_driver.cpp
index ce649c688..38d25cb45 100644
--- a/radio/src/targets/horus/trainer_driver.cpp
+++ b/radio/src/targets/horus/trainer_driver.cpp
@@ -20,10 +20,6 @@
 
 #include "opentx.h"
 
-#if defined(SBUS_TRAINER)
-Fifo<uint8_t, 32> trainerSbusFifo;
-#endif
-
 void trainerSendNextFrame();
 
 void init_trainer_ppm()
@@ -174,4 +170,4 @@ int sbusGetByte(uint8_t * byte)
     default:
       return false;
   }
-}
\ No newline at end of file
+}