diff --git a/mlair/run_modules/post_processing.py b/mlair/run_modules/post_processing.py
index 5d687dc2c86cc3681dfaa6b103bd207593e969f6..dfcc9edb15b33d8020c094ca81af5332e01782bc 100644
--- a/mlair/run_modules/post_processing.py
+++ b/mlair/run_modules/post_processing.py
@@ -930,7 +930,7 @@ class PostProcessing(RunEnvironment):
                 model_list = None
 
             # test errors of competitors
-            for model_type in remove_items(model_list or [], list(errors.keys())):
+            for model_type in (model_list or []):
                 if self.observation_indicator not in combined.coords[self.model_type_dim]:
                     continue
                 if model_type not in errors.keys():