diff --git a/src/agenda_culturel/import_tasks/extractor.py b/src/agenda_culturel/import_tasks/extractor.py
index 13f9a55..7870a7d 100644
--- a/src/agenda_culturel/import_tasks/extractor.py
+++ b/src/agenda_culturel/import_tasks/extractor.py
@@ -10,6 +10,8 @@ def remove_accents(input_str):
 
 
 class Extractor(ABC):
+    url_referer=None
+
     def __init__(self):
         self.header = {}
         self.events = []
diff --git a/src/agenda_culturel/import_tasks/generic_extractors.py b/src/agenda_culturel/import_tasks/generic_extractors.py
index 62758a0..d212624 100644
--- a/src/agenda_culturel/import_tasks/generic_extractors.py
+++ b/src/agenda_culturel/import_tasks/generic_extractors.py
@@ -47,7 +47,6 @@ class GGCalendar:
 # - then for each document downloaded from these urls, build the events
 # This class is an abstract class
 class TwoStepsExtractor(Extractor):
-    url_referer=None
 
     def __init__(self):
         super().__init__()