diff --git a/cores/arduino/HardwareTimer.cpp b/cores/arduino/HardwareTimer.cpp
index 3c325d287c..424770b286 100644
--- a/cores/arduino/HardwareTimer.cpp
+++ b/cores/arduino/HardwareTimer.cpp
@@ -35,9 +35,6 @@
 /* Private Variables */
 timerObj_t *HardwareTimer_Handle[TIMER_NUM] = {NULL};
 
-IRQn_Type getTimerUpIrq(TIM_TypeDef *tim);
-IRQn_Type getTimerCCIrq(TIM_TypeDef *tim);
-
 /**
   * @brief  HardwareTimer constructor: set default configuration values
   * @param  Timer instance ex: TIM1, ...
@@ -913,6 +910,15 @@ void HardwareTimer::setPWM(uint32_t channel, PinName pin, uint32_t frequency, ui
   */
 void HardwareTimer::setInterruptPriority(uint32_t preemptPriority, uint32_t subPriority)
 {
+  // Set Update interrupt priority for immediate use
+  HAL_NVIC_SetPriority(getTimerUpIrq(_timerObj.handle.Instance), preemptPriority, subPriority);
+
+  // Set Capture/Compare interrupt priority if timer provides a unique IRQ
+  if (getTimerCCIrq(_timerObj.handle.Instance) != getTimerUpIrq(_timerObj.handle.Instance)) {
+    HAL_NVIC_SetPriority(getTimerCCIrq(_timerObj.handle.Instance), preemptPriority, subPriority);
+  }
+
+  // Store priority for use if timer is re-initialized
   _timerObj.preemptPriority = preemptPriority;
   _timerObj.subPriority = subPriority;
 }