diff --git a/workflow/nbar.py b/workflow/nbar.py
index d3fadf6..652e6fc 100755
--- a/workflow/nbar.py
+++ b/workflow/nbar.py
@@ -412,10 +412,10 @@ def run(self):
         reqs = self.requires()
         for key in reqs:
             inputs = reqs[key].input()
-            ozone_fname = value['ozone'].path
-            vapour_fname = value['vapour'].path
-            aerosol_fname = value['aerosol'].path
-            elevation_fname = value['elevation'].path
+            ozone_fname = inputs['ozone'].path
+            vapour_fname = inputs['vapour'].path
+            aerosol_fname = inputs['aerosol'].path
+            elevation_fname = inputs['elevation'].path
 
             ozone += load_value(ozone_fname)
             vapour += load_value(vapour_fname)