diff --git a/klippy/extras/controller_fan.py b/klippy/extras/controller_fan.py
index 414be8de..3c6da5da 100644
--- a/klippy/extras/controller_fan.py
+++ b/klippy/extras/controller_fan.py
@@ -12,6 +12,7 @@ class ControllerFan:
         self.printer = config.get_printer()
         self.printer.register_event_handler("klippy:ready", self.handle_ready)
         self.steppers = []
+        self.heaters = []
         self.fan = fan.PrinterFan(config)
         self.mcu = self.fan.mcu_fan.get_mcu()
         self.max_power = config.getfloat(