diff --git a/src/servers/api/chat/websocket.ts b/src/servers/api/chat/websocket.ts
index 7e87769f..cb6f9acf 100644
--- a/src/servers/api/chat/websocket.ts
+++ b/src/servers/api/chat/websocket.ts
@@ -74,6 +74,20 @@ export const DEFAULT_MODEL = 'claude-code';
  */
 export const CHAT_DEFAULT_MODEL = 'claude-code/sonnet';
 
+/**
+ * Is this stored preference actually a model, or just a harness?
+ *
+ * `claude-code` with no tier routes fine and is a legitimate value for the resume path — but as an answer
+ * to "which model should this chat use" it means "whatever the CLI picks", which is Opus. Accounts have it
+ * stored from before that distinction existed: on this machine `tasks.defaultModel` and
+ * `chat.defaultProjectModel` were both bare, which is why the picker showed `claude-code` and the change
+ * to `CHAT_DEFAULT_MODEL` appeared to do nothing.
+ *
+ * Rather than rewrite somebody's settings, a bare harness is READ as unset. The row keeps whatever it
+ * says; the meaning of "no tier chosen" is now "use the default", which is what it always meant.
+ */
+export const isTierlessModel = (model: string | null | undefined): boolean => !model || !model.includes('/');
+
 /**
  * What a commander runs on, regardless of the account's default.
  *
@@ -871,7 +885,9 @@ async function handleChat(
 
   // Provided model, then the account default, then Sonnet. NOT `DEFAULT_MODEL` — that is the bare harness
   // and means "whatever Claude Code picks", which is Opus. See `CHAT_DEFAULT_MODEL`.
-  const requested = msg.model || (await getUserDefaultModel(userId)) || CHAT_DEFAULT_MODEL;
+  const accountDefault = await getUserDefaultModel(userId);
+  const chosen = msg.model || accountDefault;
+  const requested = isTierlessModel(chosen) ? CHAT_DEFAULT_MODEL : chosen!;
 
   /*
     A conversation may change TIER mid-flight; it may not change HARNESS.
diff --git a/src/servers/api/tasks/pipeline-executor.ts b/src/servers/api/tasks/pipeline-executor.ts
index ed534818..e5a4c360 100644
--- a/src/servers/api/tasks/pipeline-executor.ts
+++ b/src/servers/api/tasks/pipeline-executor.ts
@@ -28,7 +28,10 @@ async function resolveModel(userId: number): Promise<string> {
   try {
     const settings = await getUserSettings(userId);
     const tasks = settings?.tasks as Record<string, unknown> | undefined;
-    return (tasks?.defaultModel as string) || DEFAULT_MODEL;
+    // A bare `claude-code` is a harness, not a tier — read as unset. See `isTierlessModel` in
+    // `api/chat/websocket.ts`; this machine had exactly that stored, so the default never applied.
+    const stored = tasks?.defaultModel as string | undefined;
+    return stored && stored.includes('/') ? stored : DEFAULT_MODEL;
   } catch {
     return DEFAULT_MODEL;
   }
diff --git a/src/workspaces/officerdev/src/hooks/useChat.ts b/src/workspaces/officerdev/src/hooks/useChat.ts
index cab049b1..01573cc9 100644
--- a/src/workspaces/officerdev/src/hooks/useChat.ts
+++ b/src/workspaces/officerdev/src/hooks/useChat.ts
@@ -173,8 +173,11 @@ export function useChat(initialSessionId?: string, initialModel?: string | null,
 
   useEffect(() => {
     if (existingSessionId || initialModel) return;
-    const defaultModel = (projectScoped && settings?.chat?.defaultProjectModel) || settings?.chat?.defaultModel;
-    if (defaultModel) setSelectedModel(defaultModel);
+    const stored = (projectScoped && settings?.chat?.defaultProjectModel) || settings?.chat?.defaultModel;
+    // A stored value with no `/` is the bare harness — a routing answer, not a tier. Selecting it would
+    // send it, and the server would then honour a "choice" that means "whatever the CLI picks", i.e. Opus.
+    // Leaving it unselected lets the server apply CHAT_DEFAULT_MODEL, which is the point of that constant.
+    if (stored && stored.includes('/')) setSelectedModel(stored);
   }, [existingSessionId, initialModel, settings, projectScoped]);
 
   // Sync selectedModel when initialModel changes (e.g. resuming a session)