diff --git a/normalizer/normalizer-system-type/classify_structure.py b/normalizer/normalizer-system-type/classify_structure.py
index 6832ae95b1e78c5710e14a629e38c9cb5fc572b8..a65587b1d145ddb8484fc2bdb80b2ed758857ad3 100644
--- a/normalizer/normalizer-system-type/classify_structure.py
+++ b/normalizer/normalizer-system-type/classify_structure.py
@@ -91,7 +91,6 @@ class ClassifyStructure(object):
         # Transform data into numpy arrays, don't reshape to work with old code using flat arrays
         atom_labels = np.array(atom_labels["flatData"]).reshape(atom_labels["shape"])
         atom_pos = np.array(atom_pos["flatData"]).reshape(atom_pos["shape"])
-        cell = np.array(cell["flatData"]).reshape(cell["shape"])
 
         # No further analysis will be done if there is no cell or all periodic_dimensions are False.
         # The classification will be set to 'Atom' or 'Molecule' depending on the number of atoms.
@@ -101,6 +100,7 @@ class ClassifyStructure(object):
             else:
                 self.classification = 'Molecule / Cluster'
         else:
+            cell = np.array(cell["flatData"]).reshape(cell["shape"])
             # convert to Angstrom and numpy array
             atom_pos = self.m_to_ang * atom_pos
             cell = self.m_to_ang * cell