diff --git a/packages/coding-agent/src/core/session-manager.ts b/packages/coding-agent/src/core/session-manager.ts
index aab0c0e9..b8b930d8 100644
--- a/packages/coding-agent/src/core/session-manager.ts
+++ b/packages/coding-agent/src/core/session-manager.ts
@@ -1558,8 +1558,7 @@ export class SessionManager {
 	 */
 	static continueRecent(cwd: string, sessionDir?: string): SessionManager {
 		const dir = sessionDir ? normalizePath(sessionDir) : getDefaultSessionDir(cwd);
-		const filterCwd = sessionDir !== undefined && dir !== getDefaultSessionDirPath(cwd);
-		const mostRecent = findMostRecentSession(dir, filterCwd ? cwd : undefined);
+		const mostRecent = findMostRecentSession(dir, cwd);
 		if (mostRecent) {
 			return new SessionManager(cwd, dir, mostRecent, true);
 		}
@@ -1639,10 +1638,9 @@ export class SessionManager {
 	 */
 	static async list(cwd: string, sessionDir?: string, onProgress?: SessionListProgress): Promise<SessionInfo[]> {
 		const dir = sessionDir ? normalizePath(sessionDir) : getDefaultSessionDir(cwd);
-		const filterCwd = sessionDir !== undefined && dir !== getDefaultSessionDirPath(cwd);
 		const resolvedCwd = resolvePath(cwd);
-		const sessions = (await listSessionsFromDir(dir, onProgress)).filter(
-			(session) => !filterCwd || sessionCwdMatches(session.cwd, resolvedCwd),
+		const sessions = (await listSessionsFromDir(dir, onProgress)).filter((session) =>
+			sessionCwdMatches(session.cwd, resolvedCwd),
 		);
 		sessions.sort((a, b) => b.modified.getTime() - a.modified.getTime());
 		return sessions;
diff --git a/packages/coding-agent/test/feedback.test.ts b/packages/coding-agent/test/feedback.test.ts
index 854471c0..cda4ee03 100644
--- a/packages/coding-agent/test/feedback.test.ts
+++ b/packages/coding-agent/test/feedback.test.ts
@@ -1153,7 +1153,7 @@ describe("feedback diagnostics and bundles", () => {
 			note: expect.stringContaining("re-limited after redaction"),
 		});
 		expect(result.bundle.files).toEqual(manifest.files);
-	});
+	}, 90_000);
 
 	test("redacts tail echoes using credentials discovered before both session limits", async () => {
 		const root = await makeRoot();
diff --git a/packages/coding-agent/test/session-manager/project-isolation.test.ts b/packages/coding-agent/test/session-manager/project-isolation.test.ts
new file mode 100644
index 00000000..c535b09e
--- /dev/null
+++ b/packages/coding-agent/test/session-manager/project-isolation.test.ts
@@ -0,0 +1,45 @@
+import { mkdtempSync, readFileSync, rmSync, utimesSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { SessionManager } from "../../src/core/session-manager.ts";
+import { StepSessionManager } from "../../src/step/session.ts";
+
+describe("colliding project session directories", () => {
+	const roots: string[] = [];
+	afterEach(() => {
+		vi.unstubAllEnvs();
+		for (const root of roots) rmSync(root, { recursive: true, force: true });
+		roots.length = 0;
+	});
+
+	for (const [name, manager] of [
+		["native", SessionManager],
+		["Step", StepSessionManager],
+	] as const) {
+		it(`${name} lists and continues only the current project`, async () => {
+			const root = mkdtempSync(join(tmpdir(), "step-session-isolation-"));
+			roots.push(root);
+			vi.stubEnv("STEP_CODING_AGENT_DIR", join(root, "agent"));
+			vi.stubEnv("STEP_CODING_AGENT_SESSION_DIR", undefined);
+			const projectA = join(root, "project-a");
+			const projectB = join(root, "project", "a");
+			const a = manager.create(projectA);
+			const b = manager.create(projectB);
+			expect(a.getSessionDir()).toBe(b.getSessionDir());
+			const fileA = a.getSessionFile()!;
+			const fileB = b.getSessionFile()!;
+			writeFileSync(fileA, `${JSON.stringify(a.getHeader())}\n`);
+			writeFileSync(fileB, `${JSON.stringify(b.getHeader())}\n`);
+			utimesSync(fileA, 1, 1);
+			utimesSync(fileB, 2, 2);
+			const beforeB = readFileSync(fileB, "utf8");
+
+			expect.soft((await manager.list(projectA)).map((session) => session.path)).toEqual([fileA]);
+			const continued = manager.continueRecent(projectA);
+			expect.soft(continued.getSessionFile()).toBe(fileA);
+			continued.appendMessage({ role: "user", content: "project A only", timestamp: 1 });
+			expect(readFileSync(fileB, "utf8")).toBe(beforeB);
+		});
+	}
+});
diff --git a/packages/coding-agent/vitest.config.ts b/packages/coding-agent/vitest.config.ts
index 47f4de1f..d084ae02 100644
--- a/packages/coding-agent/vitest.config.ts
+++ b/packages/coding-agent/vitest.config.ts
@@ -7,6 +7,7 @@ export default mergeConfig(
 		test: {
 			globals: true,
 			environment: "node",
+			maxWorkers: 2,
 			testTimeout: 30000,
 			unstubEnvs: true,
 			reporters: process.env.GITHUB_ACTIONS ? ["dot", "github-actions"] : ["dot"],