diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index b4b1ba6372..4001ae63bf 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -3479,6 +3479,10 @@ void Temperature::isr() {
 
   static int8_t temp_count = -1;
   static ADCSensorState adc_sensor_state = StartupDelay;
+
+  #ifndef SOFT_PWM_SCALE
+    #define SOFT_PWM_SCALE 0
+  #endif
   static uint8_t pwm_count = _BV(SOFT_PWM_SCALE);
 
   // Avoid multiple loads of pwm_count
diff --git a/Marlin/src/module/temperature.h b/Marlin/src/module/temperature.h
index 2fdd1f02c8..27aef11c7e 100644
--- a/Marlin/src/module/temperature.h
+++ b/Marlin/src/module/temperature.h
@@ -41,10 +41,6 @@
   #include "../feature/fancheck.h"
 #endif
 
-#ifndef SOFT_PWM_SCALE
-  #define SOFT_PWM_SCALE 0
-#endif
-
 #define HOTEND_INDEX TERN(HAS_MULTI_HOTEND, e, 0)
 #define E_NAME TERN_(HAS_MULTI_HOTEND, e)