diff --git a/Marlin/temperature.cpp b/Marlin/temperature.cpp
index 084559d03364dd3f1ac3d54a5941d0b7816ac3e0..3fbb0b06fdb81004c22215e740cf04aea703b977 100644
--- a/Marlin/temperature.cpp
+++ b/Marlin/temperature.cpp
@@ -64,10 +64,10 @@ int   Temperature::current_temperature_raw[HOTENDS] = { 0 },
   float Temperature::redundant_temperature = 0.0;
 #endif
 
-unsigned char Temperature::soft_pwm_bed;
+uint8_t Temperature::soft_pwm_bed;
 
 #if ENABLED(FAN_SOFT_PWM)
-  unsigned char Temperature::fanSpeedSoftPwm[FAN_COUNT];
+  uint8_t Temperature::fanSpeedSoftPwm[FAN_COUNT];
 #endif
 
 #if ENABLED(PIDTEMP)
@@ -188,10 +188,10 @@ int Temperature::minttemp_raw[HOTENDS] = ARRAY_BY_HOTENDS(HEATER_0_RAW_LO_TEMP ,
   millis_t Temperature::next_auto_fan_check_ms = 0;
 #endif
 
-unsigned char Temperature::soft_pwm[HOTENDS];
+uint8_t Temperature::soft_pwm[HOTENDS];
 
 #if ENABLED(FAN_SOFT_PWM)
-  unsigned char Temperature::soft_pwm_fan[FAN_COUNT];
+  uint8_t Temperature::soft_pwm_fan[FAN_COUNT];
 #endif
 
 #if ENABLED(FILAMENT_WIDTH_SENSOR)
@@ -482,7 +482,7 @@ int Temperature::getHeaterPower(int heater) {
     for (uint8_t f = 0; f < COUNT(fanPin); f++) {
       int8_t pin = fanPin[f];
       if (pin >= 0 && !TEST(fanDone, fanBit[f])) {
-        unsigned char newFanSpeed = TEST(fanState, fanBit[f]) ? EXTRUDER_AUTO_FAN_SPEED : 0;
+        uint8_t newFanSpeed = TEST(fanState, fanBit[f]) ? EXTRUDER_AUTO_FAN_SPEED : 0;
         // this idiom allows both digital and PWM fan outputs (see M42 handling).
         digitalWrite(pin, newFanSpeed);
         analogWrite(pin, newFanSpeed);
@@ -1414,19 +1414,19 @@ ISR(TIMER0_COMPB_vect) { Temperature::isr(); }
 
 void Temperature::isr() {
 
-  static unsigned char temp_count = 0;
+  static uint8_t temp_count = 0;
   static TempState temp_state = StartupDelay;
-  static unsigned char pwm_count = _BV(SOFT_PWM_SCALE);
+  static uint8_t pwm_count = _BV(SOFT_PWM_SCALE);
 
   // Static members for each heater
   #if ENABLED(SLOW_PWM_HEATERS)
-    static unsigned char slow_pwm_count = 0;
+    static uint8_t slow_pwm_count = 0;
     #define ISR_STATICS(n) \
-      static unsigned char soft_pwm_ ## n; \
-      static unsigned char state_heater_ ## n = 0; \
-      static unsigned char state_timer_heater_ ## n = 0
+      static uint8_t soft_pwm_ ## n; \
+      static uint8_t state_heater_ ## n = 0; \
+      static uint8_t state_timer_heater_ ## n = 0
   #else
-    #define ISR_STATICS(n) static unsigned char soft_pwm_ ## n
+    #define ISR_STATICS(n) static uint8_t soft_pwm_ ## n
   #endif
 
   // Statics per heater
diff --git a/Marlin/temperature.h b/Marlin/temperature.h
index fe6e5222053d401d59386885ac04e09dfba03be3..72f55b317cf7493787f195948d29be49b0e5c3e1 100644
--- a/Marlin/temperature.h
+++ b/Marlin/temperature.h
@@ -65,10 +65,10 @@ class Temperature {
       static float redundant_temperature;
     #endif
 
-    static unsigned char soft_pwm_bed;
+    static uint8_t soft_pwm_bed;
 
     #if ENABLED(FAN_SOFT_PWM)
-      static unsigned char fanSpeedSoftPwm[FAN_COUNT];
+      static uint8_t fanSpeedSoftPwm[FAN_COUNT];
     #endif
 
     #if ENABLED(PIDTEMP) || ENABLED(PIDTEMPBED)
@@ -209,10 +209,10 @@ class Temperature {
       static millis_t next_auto_fan_check_ms;
     #endif
 
-    static unsigned char soft_pwm[HOTENDS];
+    static uint8_t soft_pwm[HOTENDS];
 
     #if ENABLED(FAN_SOFT_PWM)
-      static unsigned char soft_pwm_fan[FAN_COUNT];
+      static uint8_t soft_pwm_fan[FAN_COUNT];
     #endif
 
     #if ENABLED(FILAMENT_WIDTH_SENSOR)