diff --git a/src/agenda_culturel/forms.py b/src/agenda_culturel/forms.py
index 3385f73..9c25b46 100644
--- a/src/agenda_culturel/forms.py
+++ b/src/agenda_culturel/forms.py
@@ -663,7 +663,7 @@ class SelectEventInList(Form):
 class MergeDuplicates(Form):
     required_css_class = "required"
 
-    checkboxes_fields = ["reference_urls", "description", "tags"]
+    checkboxes_fields = ["reference_urls", "description", "tags", "organisers"]
 
     def __init__(self, *args, **kwargs):
         self.duplicates = kwargs.pop("duplicates", None)
diff --git a/src/agenda_culturel/views/event_duplicate_views.py b/src/agenda_culturel/views/event_duplicate_views.py
index f93c6a2..2a29032 100644
--- a/src/agenda_culturel/views/event_duplicate_views.py
+++ b/src/agenda_culturel/views/event_duplicate_views.py
@@ -48,23 +48,27 @@ def update_duplicate_event(request, pk, epk):
                             if len(values) != 0:
                                 if isinstance(values[0], str):
                                     setattr(event, f["key"], "\n".join(values))
+                                elif (
+                                    values[0].__class__.__name__ == "ManyRelatedManager"
+                                ):
+                                    rels = set()
+                                    for v in values:
+                                        rels.update(v.all())
+                                    getattr(event, f["key"]).set(rels)
                                 else:
                                     setattr(event, f["key"], sum(values, []))
                         else:
-                            if f["key"] == "organisers":
-                                event.organisers.set(selected.organisers.all())
-                            else:
+                            setattr(
+                                event,
+                                f["key"],
+                                getattr(selected, f["key"]),
+                            )
+                            if f["key"] == "image":
                                 setattr(
                                     event,
-                                    f["key"],
-                                    getattr(selected, f["key"]),
+                                    "local_image",
+                                    getattr(selected, "local_image"),
                                 )
-                                if f["key"] == "image":
-                                    setattr(
-                                        event,
-                                        "local_image",
-                                        getattr(selected, "local_image"),
-                                    )
 
             event.other_versions.fix(event)
             event.save()
@@ -116,6 +120,12 @@ def merge_duplicate(request, pk):
                         else:
                             if isinstance(values[0], str):
                                 new_event_data[f["key"]] = "\n".join(values)
+                            elif values[0].__class__.__name__ == "ManyRelatedManager":
+                                new_event_data[f["key"]] = values[0]
+                                rels = set()
+                                for v in values:
+                                    rels.update(v.all())
+                                new_event_data[f["key"]].set(rels)
                             else:
                                 new_event_data[f["key"]] = sum(values, [])
                     else: