diff --git a/pyrpl/software_modules/lockbox/models/custom_lockbox_example.py b/pyrpl/software_modules/lockbox/models/custom_lockbox_example.py
index 49bf6b3b6..aa3196bf9 100644
--- a/pyrpl/software_modules/lockbox/models/custom_lockbox_example.py
+++ b/pyrpl/software_modules/lockbox/models/custom_lockbox_example.py
@@ -34,9 +34,9 @@ def calibrate(self):
         """ This is a simplified calibration method. InputSignal.calibrate works better than this in most cases. """
         self.lockbox.sweep()
         # get a curve of the signal during the sweep
-        curve = self.sweep_acquire()
+        curve,_ = self.sweep_acquire()
         # fill self.mean, min, max, rms with values from acquired curve.
-        self.get_stats_from_curve(curve=curve)
+        self.calibration_data.get_stats_from_curve(curve=curve)
 
 
 class CustomLockbox(Lockbox):