diff --git a/Firmware/stepper.cpp b/Firmware/stepper.cpp
index 6a667370..e83876b8 100644
--- a/Firmware/stepper.cpp
+++ b/Firmware/stepper.cpp
@@ -299,9 +299,11 @@ ISR(TIMER1_COMPA_vect) {
 	if (sp < SP_min) SP_min = sp;
 #endif //DEBUG_STACK_MONITOR
 
+#ifdef DEBUG_PULLUP_CRASH
     // check for faulty pull-ups enabled on thermistor inputs
     if (PORTF & 0x5F)
         pullup_error(false);
+#endif // DEBUG_PULLUP_CRASH
 
 #ifdef LIN_ADVANCE
     advance_isr_scheduler();
diff --git a/Firmware/temperature.cpp b/Firmware/temperature.cpp
index ec55c39b..c1d06c44 100755
--- a/Firmware/temperature.cpp
+++ b/Firmware/temperature.cpp
@@ -1683,9 +1683,11 @@ void adc_ready(void) //callback from adc when sampling finished
 
 FORCE_INLINE static void temperature_isr()
 {
+#ifdef DEBUG_PULLUP_CRASH
     // check for faulty pull-ups enabled on thermistor inputs
     if (PORTF & 0x5F)
         pullup_error(true);
+#endif // DEBUG_PULLUP_CRASH
 
 
 	if (!temp_meas_ready) adc_cycle();