diff --git a/ecogvis/functions/subFunctions.py b/ecogvis/functions/subFunctions.py
index 2933c58..42d3ed6 100755
--- a/ecogvis/functions/subFunctions.py
+++ b/ecogvis/functions/subFunctions.py
@@ -759,7 +759,14 @@ def BadChannelSave(self):
             aux = [False] * self.nChTotal
             for ind in self.badChannels:
                 aux[ind] = True
-            self.nwb.electrodes['bad'].data[:] = aux
+            if 'bad' not in self.nwb.electrodes:
+                self.nwb.add_electrode_column(
+                    name='bad',
+                    description='electrode identified as too noisy',
+                    data=aux,
+                )
+            else:
+                self.nwb.electrodes['bad'].data[:] = aux
 
     def DrawMarkTime(self, position):
         """Marks temporary reference line when adding a new interval."""
diff --git a/ecogvis/functions/tdt_to_nwb/chang2nwb.py b/ecogvis/functions/tdt_to_nwb/chang2nwb.py
index ce25a77..e1e28dd 100644
--- a/ecogvis/functions/tdt_to_nwb/chang2nwb.py
+++ b/ecogvis/functions/tdt_to_nwb/chang2nwb.py
@@ -565,8 +565,6 @@ def chang2nwb(blockpath, out_file_path=None, save_to_file=False, htk_config=None
         nwbfile_dict.update(metadata['NWBFile'])
     nwbfile = NWBFile(**nwbfile_dict)
 
-    nwbfile.add_electrode_column('bad', 'electrode identified as too noisy')
-
     # Electrophysiology
     ecephys_dict = {
         'Device': [{'name': 'auto_device'}],
@@ -614,6 +612,7 @@ def chang2nwb(blockpath, out_file_path=None, save_to_file=False, htk_config=None
 
     # Electrodes table
     n_electrodes = data.shape[1]
+    nwbfile.add_electrode_column('bad', 'electrode identified as too noisy')
     bad_elecs_inds = get_bad_elecs(blockpath)
     for elec_counter in range(n_electrodes):
         bad = elec_counter in bad_elecs_inds