diff --git a/web/scripts/lobby-client.test.mjs b/web/scripts/lobby-client.test.mjs
index cfb3780..3ba3a26 100644
--- a/web/scripts/lobby-client.test.mjs
+++ b/web/scripts/lobby-client.test.mjs
@@ -442,7 +442,6 @@ test("claimSeat, assignBot, inviteHandle, kickSeat, setScenario, sendChat and se
   lobby.sendChat("garboil");
   lobby.setReady(true);
   lobby.setReady(false);
-  lobby.setLock("TraineeA", true);
   lobby.makeHost("did:plc:rival");
 
   assert.deepEqual(socket.sent, [
@@ -454,7 +453,6 @@ test("claimSeat, assignBot, inviteHandle, kickSeat, setScenario, sendChat and se
     { type: "chat", text: "garboil" },
     { type: "setReady", ready: true },
     { type: "setReady", ready: false },
-    { type: "setLock", slot: "TraineeA", locked: true },
     { type: "makeHost", did: "did:plc:rival" },
   ]);
 });
diff --git a/web/src/api.ts b/web/src/api.ts
index 083cc67..84fc3fa 100644
--- a/web/src/api.ts
+++ b/web/src/api.ts
@@ -793,12 +793,6 @@ export interface LobbySocket {
    * only answer.
    */
   setTeam(slot: string, team: number | null): void;
-  /**
-   * Holds `slot` open for somebody, or lets it go. The host's, and refused
-   * silently for anybody else — a locked slot never satisfies "every slot
-   * is claimed", so a lobby cannot deploy with one still empty.
-   */
-  setLock(slot: string, locked: boolean): void;
   /**
    * Hands the lobby to a seated player. The host's own to give, and the way
    * a host who has to leave does not take the lobby with them.
@@ -846,7 +840,12 @@ export interface LobbyCallbacks {
   /** The full seat map, sent on connect and after every successful claim. */
   onSeats(seats: MatchPlayer[]): void;
   /** The slots the host is holding open for somebody, sorted. A full
-   * snapshot, sent on connect and after every change. */
+   * snapshot, sent on connect and after every change.
+   *
+   * Nothing in this client sets one: the lobby's Hold control went with the
+   * seat control's redesign, and there is no `setLock` sender any more. This
+   * is what a lock set by another client, or by an older one, reads as here
+   * — the API still keeps and broadcasts them. */
   onLocked(slots: string[]): void;
   /**
    * Everyone with a socket open, sorted by DID — a full snapshot, sent on
@@ -991,9 +990,6 @@ export function connectLobby(
     setTeam(slot, team) {
       send({ type: "setTeam", slot, team });
     },
-    setLock(slot, locked) {
-      send({ type: "setLock", slot, locked });
-    },
     makeHost(did) {
       send({ type: "makeHost", did });
     },