diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
index a019cdb700..efd73574ca 100644
--- a/Marlin/Configuration.h
+++ b/Marlin/Configuration.h
@@ -1889,8 +1889,9 @@
 // Use software PWM to drive the fan, as for the heaters. This uses a very low frequency
 // which is not as annoying as with the hardware PWM. On the other hand, if this frequency
 // is too low, you should also increment SOFT_PWM_SCALE.
-//#define FAN_SOFT_PWM
-
+#if ENABLED(TREX3)
+  #define FAN_SOFT_PWM
+#endif
 // Incrementing this by 1 will double the software PWM frequency,
 // affecting heaters, and the fan if FAN_SOFT_PWM is enabled.
 // However, control resolution will be halved for each increment;