diff --git a/klippy/extras/pid_calibrate.py b/klippy/extras/pid_calibrate.py
index 0cad07f5..2bc6566c 100644
--- a/klippy/extras/pid_calibrate.py
+++ b/klippy/extras/pid_calibrate.py
@@ -34,6 +34,8 @@ class PIDCalibrate:
         heater.set_control(old_control)
         if write_file:
             calibrate.write_file('/tmp/heattest.txt')
+        if calibrate.check_busy(0., 0., 0.):
+            raise gcmd.error("pid_calibrate interrupted")
         # Log and report results
         Kp, Ki, Kd = calibrate.calc_final_pid()
         logging.info("Autotune: final: Kp=%f Ki=%f Kd=%f", Kp, Ki, Kd)