diff --git a/py4DSTEM/tomography/tomography.py b/py4DSTEM/tomography/tomography.py
index 8d3f25ead..a100a0fb6 100644
--- a/py4DSTEM/tomography/tomography.py
+++ b/py4DSTEM/tomography/tomography.py
@@ -1216,8 +1216,7 @@ def _calculate_update(
             )[:, None]
         )
         diffraction_patterns_resampled = diffraction_patterns_resampled[ind]
-        update = diffraction_patterns_resampled
-        # - object_sliced
+        update = diffraction_patterns_resampled - object_sliced
 
         error = xp.mean(update.ravel() ** 2) / xp.mean(
             diffraction_patterns_projected.ravel() ** 2