diff --git a/Marlin/src/module/planner.cpp b/Marlin/src/module/planner.cpp
index e8213917c6..ba0565407e 100644
--- a/Marlin/src/module/planner.cpp
+++ b/Marlin/src/module/planner.cpp
@@ -1184,7 +1184,7 @@ void Planner::recalculate(const_float_t safe_exit_speed_sqr) {
   void Planner::sync_fan_speeds(uint8_t (&fan_speed)[FAN_COUNT]) {
 
     #if defined(FAN_MULTIPLIER)
-      #define _CALC_FAN_SPEED(f) CALC_FAN_SPEED(thermalManager.compute_multiplied_fan(f)) 
+      #define _CALC_FAN_SPEED(f) CALC_FAN_SPEED(thermalManager.compute_multiplied_fan(f))
     #else
       #define _CALC_FAN_SPEED(f) CALC_FAN_SPEED(f)
     #endif
diff --git a/Marlin/src/module/temperature.cpp b/Marlin/src/module/temperature.cpp
index 221d1e9047..1c93326fb2 100644
--- a/Marlin/src/module/temperature.cpp
+++ b/Marlin/src/module/temperature.cpp
@@ -291,7 +291,9 @@ PGMSTR(str_t_heating_failed, STR_T_HEATING_FAILED);
   }
 
   uint8_t Temperature::compute_multiplied_fan(uint8_t speed){
-    return constrain(speed * fan_multiplier, 1, 255);
+    if (!speed) return 0;
+    float new_speed = speed * fan_multiplier;
+    return constrain(new_speed, 1, 255);
   }
 
   float Temperature::get_fan_multiplier(){