diff --git a/FastCCD.py b/FastCCD.py
index 612eec5177117b2d8796a5ca64eba8d623af3bdd..32e21ab0816bc0aaba3bb0c1ef56b7d6b34d8975 100644
--- a/FastCCD.py
+++ b/FastCCD.py
@@ -630,7 +630,7 @@ def process_one_module(job):
         data_pumped = ds.where(ds['FastADC5'] > 0, drop=True).groupby('scan_variable').sum('trainId')
         data_unpumped = ds.where(ds['FastADC5'] < 1, drop=True).groupby('scan_variable').sum('trainId')
                    
-        module_data = data_pumped['fastccd'].to_dataset('pumped')
+        module_data = data_pumped['fastccd'].to_dataset(name='pumped')
         module_data['unpumped'] = data_unpumped['fastccd']   
         module_data['sum_count_pumped'] = data_pumped['sum_count']
         module_data['sum_count_unpumped'] = data_unpumped['sum_count']