diff --git a/modules/client/rooms/leave.cc b/modules/client/rooms/leave.cc
index 9c5d9a216..b83ef156f 100644
--- a/modules/client/rooms/leave.cc
+++ b/modules/client/rooms/leave.cc
@@ -23,14 +23,40 @@ post__leave(client &client,
 	};
 
 	if(!room.has("m.room.member", request.user_id))
-		throw m::error
+	{
+		const m::user::room user_room
 		{
-			http::NOT_MODIFIED, "M_TARGET_NOT_IN_ROOM",
-			"The user %s has no membership state in %s",
-			string_view{request.user_id},
-			string_view{room_id},
+			request.user_id
 		};
 
+		// In case the user's user room falls out of sync with the real room
+		// state; we directly set the user's user room state.
+		if(!user_room.has("ircd.member", room_id))
+			throw m::error
+			{
+				http::NOT_MODIFIED, "M_TARGET_NOT_IN_ROOM",
+				"The user %s has no membership state in %s",
+				string_view{request.user_id},
+				string_view{room_id},
+			};
+
+		const auto event_id
+		{
+			send(user_room, request.user_id, "ircd.member", room_id, json::members
+			{
+				{ "membership", "leave" }
+			})
+		};
+
+		return resource::response
+		{
+			client, http::OK, json::members
+			{
+				{ "event_id", event_id }
+			}
+		};
+	}
+
 	const auto event_id
 	{
 		m::leave(room, request.user_id)