diff --git a/src/resources/extensions/gsd/commands-handlers.ts b/src/resources/extensions/gsd/commands-handlers.ts
index e87e89bbc..b40b7bc25 100644
--- a/src/resources/extensions/gsd/commands-handlers.ts
+++ b/src/resources/extensions/gsd/commands-handlers.ts
@@ -20,7 +20,8 @@ import {
   selectDoctorScope,
   filterDoctorIssues,
 } from "./doctor.js";
-import { isAutoActive } from "./auto.js";
+import { isAutoActive, checkRemoteAutoSession } from "./auto.js";
+import { getAutoWorktreePath } from "./auto-worktree.js";
 import { projectRoot } from "./commands/context.js";
 import { loadPrompt } from "./prompt-loader.js";
 
@@ -222,7 +223,19 @@ export async function handleSteer(change: string, ctx: ExtensionCommandContext,
   const sid = state.activeSlice?.id ?? "none";
   const tid = state.activeTask?.id ?? "none";
   const appliedAt = `${mid}/${sid}/${tid}`;
-  await appendOverride(basePath, change, appliedAt);
+
+  // Resolve the correct target path: only route to a worktree when auto-mode
+  // is actively running there (in-process or remote). A worktree directory may
+  // exist from a previous session without being the active runtime path —
+  // writing there without a live session would silently drop the override.
+  const autoRunning = isAutoActive() || checkRemoteAutoSession(basePath).running;
+  const wtPath = autoRunning && mid !== "none"
+    ? getAutoWorktreePath(basePath, mid)
+    : null;
+  const targetPath = wtPath ?? basePath;
+  await appendOverride(targetPath, change, appliedAt);
+
+  const overrideLoc = wtPath ? "worktree `.gsd/OVERRIDES.md`" : "`.gsd/OVERRIDES.md`";
 
   if (isAutoActive()) {
     pi.sendMessage({
@@ -232,14 +245,14 @@ export async function handleSteer(change: string, ctx: ExtensionCommandContext,
         "",
         `**Override:** ${change}`,
         "",
-        "This override has been saved to `.gsd/OVERRIDES.md` and will be injected into all future task prompts.",
+        `This override has been saved to ${overrideLoc} and will be injected into all future task prompts.`,
         "A document rewrite unit will run before the next task to propagate this change across all active plan documents.",
         "",
         "If you are mid-task, finish your current work respecting this override. The next dispatched unit will be a document rewrite.",
       ].join("\n"),
       display: false,
     }, { triggerTurn: true });
-    ctx.ui.notify(`Override registered: "${change}". Will be applied before next task dispatch.`, "info");
+    ctx.ui.notify(`Override registered (${overrideLoc}): "${change}". Will be applied before next task dispatch.`, "info");
   } else {
     pi.sendMessage({
       customType: "gsd-hard-steer",
@@ -248,13 +261,13 @@ export async function handleSteer(change: string, ctx: ExtensionCommandContext,
         "",
         `**Override:** ${change}`,
         "",
-        "This override has been saved to `.gsd/OVERRIDES.md`.",
-        "Before continuing, read `.gsd/OVERRIDES.md` and update the current plan documents to reflect this change.",
+        `This override has been saved to ${overrideLoc}.`,
+        `Before continuing, read ${overrideLoc} and update the current plan documents to reflect this change.`,
         "Focus on: active slice plan, incomplete task plans, and DECISIONS.md.",
       ].join("\n"),
       display: false,
     }, { triggerTurn: true });
-    ctx.ui.notify(`Override registered: "${change}". Update plan documents to reflect this change.`, "info");
+    ctx.ui.notify(`Override registered (${overrideLoc}): "${change}". Update plan documents to reflect this change.`, "info");
   }
 }
 
diff --git a/src/resources/extensions/gsd/tests/steer-worktree-path.test.ts b/src/resources/extensions/gsd/tests/steer-worktree-path.test.ts
new file mode 100644
index 000000000..137eb6cd6
--- /dev/null
+++ b/src/resources/extensions/gsd/tests/steer-worktree-path.test.ts
@@ -0,0 +1,108 @@
+// GSD Extension - Steer Worktree Path Resolution Test
+// Regression test for #3476: /gsd steer must write overrides to the worktree .gsd/,
+// not the project root .gsd/, when a worktree is active.
+
+import { describe, test, beforeEach, afterEach } from "node:test";
+import assert from "node:assert/strict";
+import { mkdtempSync, mkdirSync, existsSync, readFileSync, rmSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { appendOverride, loadActiveOverrides } from "../files.ts";
+import { getAutoWorktreePath } from "../auto-worktree.ts";
+
+describe("steer worktree path resolution (#3476)", () => {
+  let projectRoot: string;
+  let worktreePath: string;
+
+  beforeEach(() => {
+    projectRoot = mkdtempSync(join(tmpdir(), "gsd-steer-wt-"));
+    mkdirSync(join(projectRoot, ".gsd"), { recursive: true });
+
+    // Simulate a worktree with its own .gsd directory
+    worktreePath = join(projectRoot, ".gsd", "worktrees", "M001");
+    mkdirSync(join(worktreePath, ".gsd"), { recursive: true });
+  });
+
+  afterEach(() => {
+    rmSync(projectRoot, { recursive: true, force: true });
+  });
+
+  test("appendOverride writes to worktree .gsd/ when worktree path is used", async () => {
+    await appendOverride(worktreePath, "Use Postgres instead of SQLite", "M001/S01/T01");
+
+    // Override should be in the worktree .gsd/
+    const wtOverrides = join(worktreePath, ".gsd", "OVERRIDES.md");
+    assert.ok(existsSync(wtOverrides), "override file exists in worktree .gsd/");
+
+    const content = readFileSync(wtOverrides, "utf-8");
+    assert.ok(content.includes("Use Postgres instead of SQLite"), "override content is correct");
+
+    // Override should NOT be in the project root .gsd/
+    const rootOverrides = join(projectRoot, ".gsd", "OVERRIDES.md");
+    assert.ok(!existsSync(rootOverrides), "no override file in project root .gsd/");
+  });
+
+  test("loadActiveOverrides reads from worktree .gsd/ when worktree path is used", async () => {
+    await appendOverride(worktreePath, "Switch to JWT auth", "M001/S02/T01");
+
+    // Loading from worktree should find the override
+    const wtOverrides = await loadActiveOverrides(worktreePath);
+    assert.equal(wtOverrides.length, 1, "one active override in worktree");
+    assert.equal(wtOverrides[0].change, "Switch to JWT auth");
+
+    // Loading from project root should find nothing
+    const rootOverrides = await loadActiveOverrides(projectRoot);
+    assert.equal(rootOverrides.length, 0, "no overrides in project root");
+  });
+
+  test("appendOverride falls back to project root when no worktree exists", async () => {
+    await appendOverride(projectRoot, "Use Redis cache", "M001/S01/T01");
+
+    const rootOverrides = join(projectRoot, ".gsd", "OVERRIDES.md");
+    assert.ok(existsSync(rootOverrides), "override file exists in project root .gsd/");
+
+    const content = readFileSync(rootOverrides, "utf-8");
+    assert.ok(content.includes("Use Redis cache"), "override content is correct");
+  });
+
+  test("getAutoWorktreePath returns null for worktree without valid .git file", () => {
+    // The worktree directory exists but has no .git file — this is an inactive/
+    // leftover worktree. getAutoWorktreePath must return null so handleSteer
+    // does not route overrides to a dead worktree.
+    const result = getAutoWorktreePath(projectRoot, "M001");
+    assert.equal(result, null, "returns null for worktree without .git file");
+  });
+
+  test("override routing: inactive worktree directory should not receive overrides", async () => {
+    // Simulate the handleSteer path-resolution logic:
+    // When no auto-mode is running, even if a worktree dir exists,
+    // overrides must go to the project root.
+    const autoRunning = false; // no live session
+    const wtPath = autoRunning ? getAutoWorktreePath(projectRoot, "M001") : null;
+    const targetPath = wtPath ?? projectRoot;
+
+    await appendOverride(targetPath, "Should go to project root", "M001/S01/T01");
+
+    const rootOverrides = join(projectRoot, ".gsd", "OVERRIDES.md");
+    const wtOverrides = join(worktreePath, ".gsd", "OVERRIDES.md");
+
+    assert.ok(existsSync(rootOverrides), "override written to project root");
+    assert.ok(!existsSync(wtOverrides), "override NOT written to inactive worktree");
+  });
+
+  test("override routing: active worktree with valid .git should receive overrides", async () => {
+    // Simulate the handleSteer path-resolution logic with active auto-mode.
+    // getAutoWorktreePath requires a valid .git file, so even with autoRunning=true,
+    // it returns null for our test worktree (no real .git). This confirms the
+    // double-gate: both autoRunning AND valid worktree must be true.
+    const autoRunning = true;
+    const wtPath = autoRunning ? getAutoWorktreePath(projectRoot, "M001") : null;
+    const targetPath = wtPath ?? projectRoot;
+
+    // Without a valid .git file, falls back to project root
+    await appendOverride(targetPath, "Falls back without .git", "M001/S01/T01");
+
+    const rootOverrides = join(projectRoot, ".gsd", "OVERRIDES.md");
+    assert.ok(existsSync(rootOverrides), "override written to project root (no valid .git in worktree)");
+  });
+});