diff --git a/src/agenda_culturel/models.py b/src/agenda_culturel/models.py
index 02cbb1d..9c4d76d 100644
--- a/src/agenda_culturel/models.py
+++ b/src/agenda_culturel/models.py
@@ -910,13 +910,15 @@ class ModerationAnswer(models.Model):
 
     def valid_event(self, event):
         if event.tags:
-            for t in self.adds_tags:
-                if t not in event.tags:
-                    return False
+            if self.adds_tags:
+                for t in self.adds_tags:
+                    if t not in event.tags:
+                        return False
 
-            for t in self.removes_tags:
-                if t in event.tags:
-                    return False
+            if self.removes_tags:
+                for t in self.removes_tags:
+                    if t in event.tags:
+                        return False
 
             return True
         else: