2 files changed, 2 insertions, 1 deletions
diff --git a/changelog.d/18029.bugfix b/changelog.d/18029.bugfix
new file mode 100644
index 0000000000..f7036fe9fc
--- /dev/null
+++ b/changelog.d/18029.bugfix
@@ -0,0 +1 @@
+Fix a bug preventing the admin redaction endpoint from working on messages from remote users.
diff --git a/synapse/handlers/admin.py b/synapse/handlers/admin.py
index d1194545ae..f3e7790d43 100644
--- a/synapse/handlers/admin.py
+++ b/synapse/handlers/admin.py
@@ -473,7 +473,7 @@ class AdminHandler:
                     "type": EventTypes.Redaction,
                     "content": {"reason": reason} if reason else {},
                     "room_id": room,
-                    "sender": user_id,
+                    "sender": requester.user.to_string(),
                 }
                 if room_version.updated_redaction_rules:
                     event_dict["content"]["redacts"] = event.event_id