diff --git a/src/actipy/reader.py b/src/actipy/reader.py
index 56325f3..1c8138f 100644
--- a/src/actipy/reader.py
+++ b/src/actipy/reader.py
@@ -73,7 +73,7 @@ def read_device(input_file,
 
     if calibrate_gravity:
         timer.start("Gravity calibration...")
-        data, info_calib = P.calibrate_gravity(data)
+        data, info_calib = P.calibrate_gravity(data, return_coeffs=False)
         info.update(info_calib)
         timer.stop()