diff --git a/geotrek/trekking/parsers.py b/geotrek/trekking/parsers.py
index 0e93821ca6..78cb050a91 100644
--- a/geotrek/trekking/parsers.py
+++ b/geotrek/trekking/parsers.py
@@ -667,6 +667,7 @@ def filter_source(self, src, val):
 
     def filter_difficulty(self, src, val):
         types_clientele = val
+        difficulty_level = None
         for tc in types_clientele:
             if tc['id'] in self.types_clientele_ids_as_difficulty_levels:
                 difficulty_level = tc