diff --git a/combo_plugin_gnm/templatetags/gnm.py b/combo_plugin_gnm/templatetags/gnm.py
index 0ae941a..ed8f783 100644
--- a/combo_plugin_gnm/templatetags/gnm.py
+++ b/combo_plugin_gnm/templatetags/gnm.py
@@ -208,7 +208,7 @@ def get_slots_from_mdr_format(data, base_datetime):
 
 def parse_opening_hours_data(mairie_data):
     """Parse every known openinghours data formats"""
-    for openinghours in mairie_data.get('openinghours', []):
+    for openinghours in mairie_data.get('openinghours') or []:
         # format is comma-separated days and/or intervals, or only one day
         try:
             groups = re.match(