diff --git a/radio/src/targets/horus/extmodule_driver.cpp b/radio/src/targets/horus/extmodule_driver.cpp
index bcbeb7f07..5c628edf1 100644
--- a/radio/src/targets/horus/extmodule_driver.cpp
+++ b/radio/src/targets/horus/extmodule_driver.cpp
@@ -116,7 +116,7 @@ void extmodulePxx1PulsesStart()
 
 #if defined(PCBX10) || PCBREV >= 13
   EXTMODULE_TIMER->CCR3 = 18;
-  EXTMODULE_TIMER->CCER = TIM_CCER_CC3E | TIM_CCER_CC3NE;
+  EXTMODULE_TIMER->CCER = TIM_CCER_CC3E | TIM_CCER_CC3NE | TIM_CCER_CC3P | TIM_CCER_CC3NP;
   EXTMODULE_TIMER->CCMR2 = TIM_CCMR2_OC3M_2 | TIM_CCMR2_OC3M_0; // Force O/P high
   EXTMODULE_TIMER->BDTR = TIM_BDTR_MOE; // Enable outputs
   EXTMODULE_TIMER->EGR = 1; // Restart
@@ -162,7 +162,7 @@ void extmoduleSerialStart(uint32_t /*baudrate*/, uint32_t period_half_us, bool i
 
 #if defined(PCBX10) || PCBREV >= 13
   EXTMODULE_TIMER->CCR3 = 0;
-  EXTMODULE_TIMER->CCER = TIM_CCER_CC3E | (inverted ? 0 : TIM_CCER_CC3P);
+  EXTMODULE_TIMER->CCER = TIM_CCER_CC3E | TIM_CCER_CC3P;
   EXTMODULE_TIMER->CCMR2 = TIM_CCMR2_OC3M_2 | TIM_CCMR2_OC3M_0; // Force O/P high
   EXTMODULE_TIMER->BDTR = TIM_BDTR_MOE; // Enable outputs
   EXTMODULE_TIMER->EGR = 1; // Restart