diff --git a/src/schnetpack/atomistic/atomwise.py b/src/schnetpack/atomistic/atomwise.py
index 5443de025..98ef8a1d4 100644
--- a/src/schnetpack/atomistic/atomwise.py
+++ b/src/schnetpack/atomistic/atomwise.py
@@ -69,14 +69,14 @@ def forward(self, inputs: Dict[str, torch.Tensor]) -> Dict[str, torch.Tensor]:
 
         # aggregate
         if self.aggregation_mode is not None:
-            if self.aggregation_mode == "avg":
-                y = y / inputs[properties.n_atoms][:, None]
-
             idx_m = inputs[properties.idx_m]
             maxm = int(idx_m[-1]) + 1
             y = snn.scatter_add(y, idx_m, dim_size=maxm)
             y = torch.squeeze(y, -1)
 
+            if self.aggregation_mode == "avg":
+                y = y / inputs[properties.n_atoms]
+
         inputs[self.output_key] = y
         return inputs
 
diff --git a/src/schnetpack/interfaces/ase_interface.py b/src/schnetpack/interfaces/ase_interface.py
index 2758218ce..1e6ec11d1 100644
--- a/src/schnetpack/interfaces/ase_interface.py
+++ b/src/schnetpack/interfaces/ase_interface.py
@@ -76,9 +76,6 @@ def __init__(
         else:
             raise AtomsConverterError(f"Unrecognized precision {dtype}")
 
-        for t in self.transforms:
-            t.preprocessor()
-
     def __call__(self, atoms: Atoms):
         """
 
@@ -162,7 +159,7 @@ def __init__(
         self.property_units = {
             self.energy: convert_units(energy_units, "eV"),
             self.forces: convert_units(forces_units, "eV/Angstrom"),
-            self.stress: convert_units(stress_units, "eV/A/A/A"),
+            self.stress: convert_units(stress_units, "eV/Ang/Ang/Ang"),
         }
 
     def calculate(