diff --git a/packages/testing/janitor/src/cli.ts b/packages/testing/janitor/src/cli.ts
index b4c41e4e393..365ebe245a7 100644
--- a/packages/testing/janitor/src/cli.ts
+++ b/packages/testing/janitor/src/cli.ts
@@ -22,6 +22,7 @@ import {
 	distributeShards,
 	selectTests,
 	changedRuntimeDepsFromManifests,
+	changedOverrideTargets,
 } from '@n8n/test-impact';
 import * as fs from 'node:fs';
 import * as path from 'node:path';
@@ -78,7 +79,7 @@ import {
 	formatMethodUsageIndexJSON,
 } from './core/method-usage-analyzer.js';
 import { createProject } from './core/project-loader.js';
-import { readLockfileImporters } from './core/read-lockfile-importers.js';
+import { readLockfileImporters, readRuntimeClosure } from './core/read-lockfile-importers.js';
 import { readManifestDiffs, readTsconfigDiffs } from './core/read-manifest-diffs.js';
 import { toJSON, toConsole } from './core/reporter.js';
 import { filterToFailedSpecs } from './core/retry-filter.js';
@@ -726,10 +727,18 @@ function runSelect(options: CliOptions): void {
 	// Only parse the (large) lockfile when a RUNTIME dependency actually changed —
 	// the only case the dep-graph selector (389) acts on. A devDep-only manifest
 	// change would parse it for nothing.
-	const lockfileImporters =
-		manifests && changedRuntimeDepsFromManifests(manifests).length > 0
-			? readLockfileImporters()
-			: undefined;
+	const runtimeDepsChanged = manifests
+		? changedRuntimeDepsFromManifests(manifests).length > 0
+		: false;
+	const lockfileImporters = runtimeDepsChanged ? readLockfileImporters() : undefined;
+	// The closure classifies override pins; a runtime-dep change already forces
+	// broad, so don't compute it then.
+	const overridesChanged =
+		!runtimeDepsChanged &&
+		Object.values(manifests ?? {}).some(({ before, after }) => {
+			const targets = changedOverrideTargets(before, after);
+			return targets === null || targets.length > 0;
+		});
 	const result = selectTests({
 		changedFiles,
 		mapFile: options.mapFile,
@@ -737,6 +746,7 @@ function runSelect(options: CliOptions): void {
 		manifests,
 		tsconfigs,
 		lockfileImporters,
+		runtimeClosure: overridesChanged ? readRuntimeClosure() : undefined,
 	});
 	console.log(JSON.stringify(result));
 }
diff --git a/packages/testing/janitor/src/core/read-lockfile-importers.ts b/packages/testing/janitor/src/core/read-lockfile-importers.ts
index f5d9869512c..18528f12394 100644
--- a/packages/testing/janitor/src/core/read-lockfile-importers.ts
+++ b/packages/testing/janitor/src/core/read-lockfile-importers.ts
@@ -8,27 +8,44 @@
  * lockfile) returns `{}`, which makes the dep-graph selector contribute nothing
  * (the change then resolves through the coverage map alone — fail-open).
  */
-import { RUNTIME_SECTIONS } from '@n8n/test-impact';
+import {
+	RUNTIME_SECTIONS,
+	runtimeClosure,
+	type LockfileImporters,
+	type LockfileSnapshots,
+} from '@n8n/test-impact';
 import { existsSync, readFileSync } from 'node:fs';
 import { join } from 'node:path';
 import { parse } from 'yaml';
 
 import { getGitRoot } from '../utils/git-operations.js';
 
-type ImporterSections = Record<string, Record<string, unknown> | undefined>;
+type Lockfile = {
+	importers?: LockfileImporters;
+	snapshots?: LockfileSnapshots;
+};
 
-export function readLockfileImporters(): Record<string, string[]> {
+/**
+ * Closure seed: `packages/cli` is the `n8n` package the E2E container runs;
+ * its workspace `link:` edges cover the rest. See {@link runtimeClosure} for
+ * why this must not be "every importer".
+ */
+const DEPLOY_ROOTS = ['packages/cli'] as const;
+
+/** Parse the lockfile once, or `undefined` on any failure (fail-open). */
+function readLockfile(): Lockfile | undefined {
 	const lockPath = join(getGitRoot(process.cwd()), 'pnpm-lock.yaml');
-	if (!existsSync(lockPath)) return {};
-	let doc: { importers?: Record<string, ImporterSections> };
+	if (!existsSync(lockPath)) return undefined;
 	try {
-		doc = parse(readFileSync(lockPath, 'utf8')) as typeof doc;
+		return parse(readFileSync(lockPath, 'utf8')) as Lockfile;
 	} catch {
-		return {};
+		return undefined;
 	}
-	const importers = doc?.importers ?? {};
+}
+
+function importersFrom(doc: Lockfile): Record<string, string[]> {
 	const out: Record<string, string[]> = {};
-	for (const [dir, sections] of Object.entries(importers)) {
+	for (const [dir, sections] of Object.entries(doc.importers ?? {})) {
 		const names = new Set<string>();
 		for (const section of RUNTIME_SECTIONS) {
 			const deps = sections?.[section];
@@ -38,3 +55,21 @@ export function readLockfileImporters(): Record<string, string[]> {
 	}
 	return out;
 }
+
+export function readLockfileImporters(): Record<string, string[]> {
+	const doc = readLockfile();
+	return doc ? importersFrom(doc) : {};
+}
+
+/**
+ * Runtime closure for classifying `pnpm.overrides` changes. `undefined` on any
+ * read failure, which keeps them broad.
+ */
+export function readRuntimeClosure(): ReadonlySet<string> | undefined {
+	const doc = readLockfile();
+	if (!doc?.snapshots || !doc.importers) return undefined;
+	return runtimeClosure(doc.importers, doc.snapshots, {
+		deployRoots: DEPLOY_ROOTS,
+		runtimeSections: RUNTIME_SECTIONS,
+	});
+}
diff --git a/packages/testing/test-impact/src/changes.test.ts b/packages/testing/test-impact/src/changes.test.ts
index 5f2ad2195dd..d8d10979a28 100644
--- a/packages/testing/test-impact/src/changes.test.ts
+++ b/packages/testing/test-impact/src/changes.test.ts
@@ -8,6 +8,8 @@ import {
 	tsconfigForcesBroad,
 	classifyManifestChange,
 	dropDevDepOnlyDeps,
+	overrideTargetName,
+	changedOverrideTargets,
 } from './changes.js';
 
 describe('isNonImpactful', () => {
@@ -228,3 +230,123 @@ describe('dropDevDepOnlyDeps (safety-critical)', () => {
 		).toEqual(files);
 	});
 });
+
+const ovr = (overrides: Record<string, string>, deps = {}, devDeps = {}) =>
+	JSON.stringify({ name: 'x', dependencies: deps, devDependencies: devDeps, pnpm: { overrides } });
+
+describe('overrideTargetName', () => {
+	it.each([
+		['@vitest/browser@<4.1.10', '@vitest/browser'],
+		['brace-expansion@5', 'brace-expansion'],
+		['node-gyp>undici', 'undici'],
+		['@babel/traverse', '@babel/traverse'],
+		['undici@7', 'undici'],
+		['a>b>@scope/c@^1.0.0', '@scope/c'],
+		['@n8n/typeorm>@sentry/node', '@sentry/node'],
+		// `>` inside a version range is not a parent separator
+		['pkg@>=2.0.0', 'pkg'],
+		['pkg@>2', 'pkg'],
+		['pkg@1||>2', 'pkg'],
+		['pkg@^1||>=2.0.0', 'pkg'],
+		['pkg@>=1||>=2', 'pkg'],
+		['a@1>b@>=2', 'b'],
+		['a@=1.2.3>b', 'b'],
+		['pkg@1=>2', 'pkg'],
+	])('%s → %s', (selector, expected) => {
+		expect(overrideTargetName(selector)).toBe(expected);
+	});
+
+	it('returns null when no package name can be extracted', () => {
+		expect(overrideTargetName('>=2.0.0')).toBeNull();
+	});
+});
+
+describe('changedOverrideTargets', () => {
+	it('returns the target when a pin is added', () => {
+		expect(changedOverrideTargets(ovr({}), ovr({ 'ws@<8.21.1': '8.21.1' }))).toEqual(['ws']);
+	});
+	it('returns the target when a pin is removed', () => {
+		expect(changedOverrideTargets(ovr({ 'ws@<8.21.1': '8.21.1' }), ovr({}))).toEqual(['ws']);
+	});
+	it('returns the target when a pin version changes', () => {
+		expect(
+			changedOverrideTargets(
+				ovr({ 'brace-expansion@5': '5.0.7' }),
+				ovr({ 'brace-expansion@5': '5.0.9' }),
+			),
+		).toEqual(['brace-expansion']);
+	});
+	it('de-duplicates selectors pinning the same package', () => {
+		expect(
+			changedOverrideTargets(ovr({}), ovr({ 'undici@7': '7.29.0', 'node-gyp>undici': '7.29.0' })),
+		).toEqual(['undici']);
+	});
+	it('ignores untouched pins', () => {
+		const same = ovr({ 'ws@<8.21.1': '8.21.1' });
+		expect(changedOverrideTargets(same, same)).toEqual([]);
+	});
+});
+
+describe('classifyManifestChange — overrides', () => {
+	it('override when only a pnpm.overrides pin moves', () => {
+		expect(classifyManifestChange(ovr({}), ovr({ 'ws@1': '1.0.1' }))).toBe('override');
+	});
+	it('runtime wins over a co-occurring override change', () => {
+		expect(
+			classifyManifestChange(ovr({}, { axios: '1' }), ovr({ 'ws@1': '1.0.1' }, { axios: '2' })),
+		).toBe('runtime');
+	});
+	it('override wins over a co-occurring devDependencies change', () => {
+		expect(
+			classifyManifestChange(
+				ovr({}, {}, { vitest: '1' }),
+				ovr({ 'ws@1': '1.0.1' }, {}, { vitest: '2' }),
+			),
+		).toBe('override');
+	});
+});
+
+describe('dropDevDepOnlyDeps — overrides (safety-critical)', () => {
+	const files = ['pnpm-lock.yaml', 'package.json'];
+	const overrideDiff = (target: string) => ({
+		'package.json': { before: ovr({}), after: ovr({ [`${target}@<2`]: '2.0.0' }) },
+	});
+	const closure = new Set(['ajv', 'fast-uri']);
+
+	it('drops when every override target is outside the runtime closure', () => {
+		expect(dropDevDepOnlyDeps(files, overrideDiff('@vitest/browser'), closure)).toEqual([]);
+	});
+	it('KEEPS when the override target is inside the runtime closure', () => {
+		expect(dropDevDepOnlyDeps(files, overrideDiff('fast-uri'), closure)).toEqual(files);
+	});
+	it('KEEPS when no closure is supplied', () => {
+		expect(dropDevDepOnlyDeps(files, overrideDiff('@vitest/browser'), undefined)).toEqual(files);
+	});
+	it('KEEPS when the closure is empty (broken walk, not proof)', () => {
+		expect(dropDevDepOnlyDeps(files, overrideDiff('@vitest/browser'), new Set())).toEqual(files);
+	});
+	it('KEEPS when any one of several targets is inside the closure', () => {
+		const manifests = {
+			'package.json': {
+				before: ovr({}),
+				after: ovr({ '@vitest/browser@<2': '2.0.0', 'fast-uri@<4': '4.0.0' }),
+			},
+		};
+		expect(dropDevDepOnlyDeps(files, manifests, closure)).toEqual(files);
+	});
+	it('KEEPS a runtime-section change even when its override target is outside the closure', () => {
+		const manifests = {
+			'package.json': {
+				before: ovr({}, { axios: '1' }),
+				after: ovr({ '@vitest/browser@<2': '2.0.0' }, { axios: '2' }),
+			},
+		};
+		expect(dropDevDepOnlyDeps(files, manifests, closure)).toEqual(files);
+	});
+	it('KEEPS when a changed selector cannot be attributed to a package', () => {
+		const manifests = {
+			'package.json': { before: ovr({}), after: ovr({ '>=2.0.0': '2.0.0' }) },
+		};
+		expect(dropDevDepOnlyDeps(files, manifests, closure)).toEqual(files);
+	});
+});
diff --git a/packages/testing/test-impact/src/changes.ts b/packages/testing/test-impact/src/changes.ts
index 290275a6ef6..788ecbea8ec 100644
--- a/packages/testing/test-impact/src/changes.ts
+++ b/packages/testing/test-impact/src/changes.ts
@@ -78,7 +78,7 @@ export function forcesBroad(file: string): boolean {
 }
 
 /** A package.json change classified by which dependency sections moved. */
-export type ManifestChangeKind = 'runtime' | 'devDep-only' | 'none';
+export type ManifestChangeKind = 'runtime' | 'devDep-only' | 'override' | 'none';
 
 type ManifestJson = Record<string, Record<string, string> | undefined>;
 /** package.json sections whose changes can reach the runtime bundle. */
@@ -115,18 +115,83 @@ function sectionChanged(before: ManifestJson, after: ManifestJson, section: stri
 	return changedKeysInSection(before, after, section).length > 0;
 }
 
+/** `pnpm.overrides` selectors changed between two manifests, as written. */
+function changedOverrideSelectors(before: ManifestJson, after: ManifestJson): string[] {
+	const b = (before.pnpm as { overrides?: Record<string, string> } | undefined)?.overrides ?? {};
+	const a = (after.pnpm as { overrides?: Record<string, string> } | undefined)?.overrides ?? {};
+	const changed: string[] = [];
+	for (const key of new Set([...Object.keys(b), ...Object.keys(a)])) {
+		if (b[key] !== a[key]) changed.push(key);
+	}
+	return changed;
+}
+
+const NPM_PACKAGE_NAME = /^(@[a-z0-9-~][a-z0-9-._~]*\/)?[a-z0-9-~][a-z0-9-._~]*$/i;
+
+/**
+ * The package an override selector pins (`node-gyp>undici` → `undici`,
+ * `@vitest/browser@<4.1.10` → `@vitest/browser`), or `null` when the selector
+ * can't be parsed with confidence — callers must then stay broad.
+ */
+export function overrideTargetName(selector: string): string | null {
+	// A range `>` (`pkg@>2`, `pkg@1||>2`) follows `@` or `|`, touches whitespace,
+	// or is `>=` — never a parent>child separator.
+	let child = selector;
+	for (let i = selector.length - 1; i > 0; i--) {
+		if (selector[i] !== '>') continue;
+		const prev = selector[i - 1];
+		const next = selector[i + 1] ?? '';
+		if (
+			prev === '@' ||
+			prev === '|' ||
+			prev === '=' ||
+			next === '=' ||
+			/\s/.test(prev) ||
+			/\s/.test(next)
+		) {
+			continue;
+		}
+		child = selector.slice(i + 1);
+		break;
+	}
+	child = child.trim();
+	// `> 0` keeps a leading scope `@` intact when stripping the version range.
+	const at = child.lastIndexOf('@');
+	const name = at > 0 ? child.slice(0, at) : child;
+	return NPM_PACKAGE_NAME.test(name) ? name : null;
+}
+
+/**
+ * Packages whose `pnpm.overrides` pin was added, removed or changed. `null`
+ * when any changed selector fails to parse — the diff can't be attributed.
+ */
+export function changedOverrideTargets(before: string, after: string): string[] | null {
+	const selectors = changedOverrideSelectors(parseManifest(before), parseManifest(after));
+	const names = new Set<string>();
+	for (const selector of selectors) {
+		const name = overrideTargetName(selector);
+		if (name === null) return null;
+		names.add(name);
+	}
+	return [...names];
+}
+
 /**
  * Classify a package.json change by the dependency sections it touched:
  *  - `runtime`     — a runtime section (dependencies / optional / peer) moved, so
  *                    it can reach the bundle the E2E suite exercises.
+ *  - `override`    — a `pnpm.overrides` pin moved; whether it reaches the
+ *                    runtime bundle takes a closure check (see {@link dropDevDepOnlyDeps}).
  *  - `devDep-only` — only devDependencies moved → cannot reach the runtime bundle.
  *  - `none`        — no dependency section moved (scripts / version / engines / …).
- * Unparseable content is treated as an empty manifest.
+ * Unparseable content is treated as an empty manifest. Checked most-impactful
+ * first: a mixed devDep+override change classifies as `override`.
  */
 export function classifyManifestChange(before: string, after: string): ManifestChangeKind {
 	const b = parseManifest(before);
 	const a = parseManifest(after);
 	if (RUNTIME_SECTIONS.some((s) => sectionChanged(b, a, s))) return 'runtime';
+	if (changedOverrideSelectors(b, a).length > 0) return 'override';
 	return sectionChanged(b, a, 'devDependencies') ? 'devDep-only' : 'none';
 }
 
@@ -217,14 +282,21 @@ export function stripDependencyFiles(files: string[]): string[] {
  * bundle, so it must not force broad. `manifests` maps each changed package.json
  * path to its before/after content (the caller reads these from git).
  *
+ * An override pins a TRANSITIVE package, which no declared section mentions —
+ * `fast-uri` (reaches runtime via `ajv`) and `@vitest/browser` (dev-only) look
+ * identical there. Only `runtimeClosure` membership can tell them apart.
+ *
  * Conservative by construction — never drops without positive evidence:
  *  - any runtime-section change → keep everything (real dep change);
  *  - a changed package.json with no supplied diff → treated as runtime;
- *  - a lockfile change with no changed package.json at all (transitive bump) → kept.
+ *  - a lockfile change with no changed package.json at all (transitive bump) → kept;
+ *  - an override change with a missing/empty closure, an unparseable selector,
+ *    or any target inside the closure → kept.
  */
 export function dropDevDepOnlyDeps(
 	files: string[],
 	manifests: Record<string, { before: string; after: string }>,
+	runtimeClosure?: ReadonlySet<string>,
 ): string[] {
 	const changedManifests = files.filter(isManifest);
 	if (changedManifests.length === 0) return files;
@@ -232,6 +304,21 @@ export function dropDevDepOnlyDeps(
 		manifests[f] ? classifyManifestChange(manifests[f].before, manifests[f].after) : 'runtime',
 	);
 	if (kinds.includes('runtime')) return files;
+
+	if (kinds.includes('override')) {
+		// An empty closure is a broken walk, not proof nothing reaches runtime.
+		if (!runtimeClosure || runtimeClosure.size === 0) return files;
+		const targets = new Set<string>();
+		for (const f of changedManifests) {
+			if (!manifests[f]) continue;
+			const names = changedOverrideTargets(manifests[f].before, manifests[f].after);
+			if (names === null) return files;
+			for (const name of names) targets.add(name);
+		}
+		if (targets.size === 0 || [...targets].some((t) => runtimeClosure.has(t))) return files;
+		return stripDependencyFiles(files);
+	}
+
 	if (!kinds.includes('devDep-only')) return files;
 	return stripDependencyFiles(files);
 }
diff --git a/packages/testing/test-impact/src/dep-graph.test.ts b/packages/testing/test-impact/src/dep-graph.test.ts
index af87efc47b6..26960e5f2da 100644
--- a/packages/testing/test-impact/src/dep-graph.test.ts
+++ b/packages/testing/test-impact/src/dep-graph.test.ts
@@ -5,7 +5,13 @@ import {
 	changedRuntimeDepsFromManifests,
 	stripDependencyFiles,
 } from './changes.js';
-import { dependentDirs } from './dep-graph.js';
+import {
+	dependentDirs,
+	runtimeClosure,
+	snapshotKeyToName,
+	type LockfileImporters,
+	type LockfileSnapshots,
+} from './dep-graph.js';
 import type { ImpactMap } from './impact-map.js';
 import { DependencyGraphStrategy } from './select/dep-graph-strategy.js';
 
@@ -111,3 +117,98 @@ describe('DependencyGraphStrategy', () => {
 		expect(r).toEqual({ specs: [], unmapped: [], mode: 'scoped' });
 	});
 });
+
+describe('snapshotKeyToName', () => {
+	it.each([
+		['ajv@8.18.0', 'ajv'],
+		['@scope/pkg@1.0.0', '@scope/pkg'],
+		// peer suffix carries `@`s — must not confuse the version separator
+		['@vitest/coverage-v8@4.1.9(vitest@4.1.9)', '@vitest/coverage-v8'],
+		['vite@5.0.0(sass@1.98.0)(terser@5.0.0)', 'vite'],
+		['plain-name', 'plain-name'],
+	])('%s → %s', (key, expected) => {
+		expect(snapshotKeyToName(key)).toBe(expected);
+	});
+});
+
+describe('runtimeClosure', () => {
+	// cli links core (runtime) → ajv → fast-uri; test-utils declares vitest but
+	// is only reachable via devDependencies, so it must stay out.
+	const importers: LockfileImporters = {
+		'packages/cli': {
+			dependencies: {
+				'n8n-core': { specifier: 'workspace:*', version: 'link:../core' },
+				axios: { specifier: '^1.0.0', version: '1.0.0' },
+			},
+			devDependencies: {
+				'test-utils': { specifier: 'workspace:*', version: 'link:../test-utils' },
+			},
+		},
+		'packages/core': {
+			dependencies: { ajv: { specifier: '^8.0.0', version: '8.18.0' } },
+		},
+		'packages/test-utils': {
+			dependencies: { vitest: { specifier: '^4.0.0', version: '4.1.9' } },
+		},
+	};
+	const snapshots: LockfileSnapshots = {
+		'ajv@8.18.0': { dependencies: { 'fast-uri': '3.1.3' } },
+		'fast-uri@3.1.3': {},
+		'axios@1.0.0': {},
+		'vitest@4.1.9': { dependencies: { '@vitest/browser': '4.1.9' } },
+		'@vitest/browser@4.1.9': {},
+	};
+	const opts = {
+		deployRoots: ['packages/cli'],
+		runtimeSections: ['dependencies', 'optionalDependencies'],
+	};
+
+	it('follows workspace link: edges from the deploy roots', () => {
+		const closure = runtimeClosure(importers, snapshots, opts);
+		expect(closure.has('ajv')).toBe(true);
+		expect(closure.has('axios')).toBe(true);
+	});
+	it('reaches a dep only present via a transitive snapshot edge (the fast-uri shape)', () => {
+		expect(runtimeClosure(importers, snapshots, opts).has('fast-uri')).toBe(true);
+	});
+	it('excludes deps of a workspace package reachable only via devDependencies (the vitest shape)', () => {
+		const closure = runtimeClosure(importers, snapshots, opts);
+		expect(closure.has('vitest')).toBe(false);
+		expect(closure.has('@vitest/browser')).toBe(false);
+	});
+	it('with empty snapshots the closure is just the declared external roots', () => {
+		expect([...runtimeClosure(importers, {}, opts)].sort()).toEqual(['ajv', 'axios']);
+	});
+	it('roots the real package behind an npm: alias in an importer (the zod-from-json-schema shape)', () => {
+		const aliased: LockfileImporters = {
+			'packages/cli': {
+				dependencies: {
+					'zod-v3': {
+						specifier: 'npm:zod-from-json-schema@^0.0.5',
+						version: 'zod-from-json-schema@0.0.5',
+					},
+				},
+			},
+		};
+		const snaps: LockfileSnapshots = {
+			'zod-from-json-schema@0.0.5': { dependencies: { zod: '3.25.76' } },
+		};
+		const closure = runtimeClosure(aliased, snaps, opts);
+		expect(closure.has('zod-from-json-schema')).toBe(true);
+		expect(closure.has('zod')).toBe(true);
+	});
+	it('follows an aliased dep inside a snapshot (the string-width-cjs shape)', () => {
+		const snaps: LockfileSnapshots = {
+			'ajv@8.18.0': { dependencies: { 'string-width-cjs': 'string-width@4.2.3' } },
+			'string-width@4.2.3': { dependencies: { 'emoji-regex': '8.0.0' } },
+		};
+		const closure = runtimeClosure(importers, snaps, opts);
+		expect(closure.has('string-width')).toBe(true);
+		expect(closure.has('emoji-regex')).toBe(true);
+	});
+	it('unknown deploy root → empty closure, no throw', () => {
+		expect(
+			runtimeClosure(importers, snapshots, { ...opts, deployRoots: ['packages/nope'] }).size,
+		).toBe(0);
+	});
+});
diff --git a/packages/testing/test-impact/src/dep-graph.ts b/packages/testing/test-impact/src/dep-graph.ts
index ec7816fa108..3ec97a25fe4 100644
--- a/packages/testing/test-impact/src/dep-graph.ts
+++ b/packages/testing/test-impact/src/dep-graph.ts
@@ -18,3 +18,141 @@ export function dependentDirs(deps: string[], importers: WorkspaceImporters): st
 	}
 	return dirs.sort();
 }
+
+/**
+ * pnpm-lock.yaml `snapshots`: resolved-package key → its dependency sections.
+ * Keys carry a version and, for peer-resolved packages, a suffix — e.g.
+ * `ajv@8.18.0`, `@vitest/coverage-v8@4.1.9(vitest@4.1.9)`.
+ */
+export type LockfileSnapshots = Record<
+	string,
+	Record<string, Record<string, string> | undefined> | undefined
+>;
+
+/**
+ * Package name from a snapshot key. The peer suffix must be stripped BEFORE
+ * looking for the version separator, because it contains `@` of its own —
+ * otherwise `@vitest/coverage-v8@4.1.9(vitest@4.1.9)` resolves to the wrong
+ * name, the variant is never visited, and the closure silently under-includes.
+ */
+export function snapshotKeyToName(key: string): string {
+	const base = key.replace(/\(.*$/, '');
+	const at = base.lastIndexOf('@');
+	return at > 0 ? base.slice(0, at) : base;
+}
+
+/**
+ * Real package behind an aliased dependency value (`string-width@4.2.3`), or
+ * null for a plain version. Aliases resolve under the REAL package's snapshot
+ * key, so a walk following only the alias name never visits them.
+ */
+function aliasedDepName(value: string): string | null {
+	const name = snapshotKeyToName(value);
+	return name === value.replace(/\(.*$/, '') ? null : name;
+}
+
+/** A dependency entry in pnpm-lock.yaml's `importers`. */
+type ImporterEntry = { specifier?: string; version?: string } | string;
+/** pnpm-lock.yaml `importers`: workspace dir → dependency sections. */
+export type LockfileImporters = Record<
+	string,
+	Record<string, Record<string, ImporterEntry> | undefined> | undefined
+>;
+
+const LINK_PREFIX = 'link:';
+
+/** The `link:` target of a workspace dependency entry, or undefined if external. */
+function workspaceLinkTarget(entry: ImporterEntry): string | undefined {
+	const candidates =
+		typeof entry === 'string' ? [entry] : [entry?.specifier ?? '', entry?.version ?? ''];
+	const link = candidates.find((v) => v.startsWith(LINK_PREFIX));
+	return link?.slice(LINK_PREFIX.length);
+}
+
+/** Resolve a `link:../foo` target, relative to the declaring package's dir. */
+function resolveLink(fromDir: string, target: string): string {
+	const segments = `${fromDir}/${target}`.split('/');
+	const out: string[] = [];
+	for (const segment of segments) {
+		if (segment === '' || segment === '.') continue;
+		if (segment === '..') out.pop();
+		else out.push(segment);
+	}
+	return out.join('/');
+}
+
+/**
+ * External dependency names the *deployed* workspace packages declare, following
+ * workspace `link:` edges through RUNTIME sections only. Runtime-only edges keep
+ * dev-only workspace packages out: `@n8n/backend-test-utils` declares `vitest`
+ * in `dependencies` but is itself reachable only via `devDependencies`.
+ */
+function deployedExternalDeps(
+	importers: LockfileImporters,
+	deployRoots: readonly string[],
+	runtimeSections: readonly string[],
+): Set<string> {
+	const visited = new Set<string>();
+	const external = new Set<string>();
+	const queue = [...deployRoots];
+	while (queue.length > 0) {
+		const dir = queue.pop();
+		if (dir === undefined || visited.has(dir)) continue;
+		visited.add(dir);
+		const sections = importers[dir];
+		if (!sections) continue;
+		for (const section of runtimeSections) {
+			for (const [name, entry] of Object.entries(sections[section] ?? {})) {
+				const link = workspaceLinkTarget(entry);
+				if (link !== undefined) {
+					queue.push(resolveLink(dir, link));
+					continue;
+				}
+				external.add(name);
+				const version = typeof entry === 'string' ? entry : (entry?.version ?? '');
+				const real = aliasedDepName(version);
+				if (real !== null) external.add(real);
+			}
+		}
+	}
+	return external;
+}
+
+/**
+ * Every package name transitively reachable from the deploy roots' runtime
+ * dependencies — a name OUTSIDE this set cannot reach the bundle E2E exercises.
+ * Errs toward including: over-inclusion costs a missed optimisation,
+ * under-inclusion would skip tests for a live runtime change.
+ */
+export function runtimeClosure(
+	importers: LockfileImporters,
+	snapshots: LockfileSnapshots,
+	opts: { deployRoots: readonly string[]; runtimeSections: readonly string[] },
+): Set<string> {
+	const { deployRoots, runtimeSections } = opts;
+	const variantsByName = new Map<string, string[]>();
+	for (const key of Object.keys(snapshots)) {
+		const name = snapshotKeyToName(key);
+		const existing = variantsByName.get(name);
+		if (existing) existing.push(key);
+		else variantsByName.set(name, [key]);
+	}
+
+	const closure = new Set<string>();
+	const queue = [...deployedExternalDeps(importers, deployRoots, runtimeSections)];
+	while (queue.length > 0) {
+		const name = queue.pop();
+		if (name === undefined || closure.has(name)) continue;
+		closure.add(name);
+		for (const key of variantsByName.get(name) ?? []) {
+			for (const section of runtimeSections) {
+				for (const [dep, version] of Object.entries(snapshots[key]?.[section] ?? {})) {
+					if (!closure.has(dep)) queue.push(dep);
+					const real = aliasedDepName(version);
+					if (real !== null && !closure.has(real)) queue.push(real);
+				}
+			}
+		}
+	}
+	return closure;
+}
diff --git a/packages/testing/test-impact/src/index.ts b/packages/testing/test-impact/src/index.ts
index 4c53a25456f..d2ff0b20f65 100644
--- a/packages/testing/test-impact/src/index.ts
+++ b/packages/testing/test-impact/src/index.ts
@@ -17,11 +17,18 @@ export {
 	dropDevDepOnlyDeps,
 	changedRuntimeDeps,
 	changedRuntimeDepsFromManifests,
+	changedOverrideTargets,
 	stripDependencyFiles,
 	RUNTIME_SECTIONS,
 	type ManifestChangeKind,
 } from './changes.js';
-export { dependentDirs, type WorkspaceImporters } from './dep-graph.js';
+export {
+	dependentDirs,
+	runtimeClosure,
+	type WorkspaceImporters,
+	type LockfileImporters,
+	type LockfileSnapshots,
+} from './dep-graph.js';
 export type { DiscoveredSpec } from './types.js';
 
 // Strategy + Pipeline selection layer.
diff --git a/packages/testing/test-impact/src/select.test.ts b/packages/testing/test-impact/src/select.test.ts
index 70e40c6a859..d96f411d708 100644
--- a/packages/testing/test-impact/src/select.test.ts
+++ b/packages/testing/test-impact/src/select.test.ts
@@ -297,3 +297,61 @@ describe('selectTests — fail-open contract', () => {
 		});
 	});
 });
+
+describe('selectTests — pnpm.overrides changes', () => {
+	let tempDir: string;
+
+	beforeEach(() => {
+		tempDir = fs.realpathSync(fs.mkdtempSync(path.join(os.tmpdir(), 'select-ovr-')));
+	});
+
+	afterEach(() => {
+		fs.rmSync(tempDir, { recursive: true, force: true });
+	});
+
+	const ALL_SPECS = ['tests/e2e/a.spec.ts', 'tests/e2e/b.spec.ts'];
+	const changedFiles = ['package.json', 'pnpm-lock.yaml'];
+
+	const setup = (target: string) => {
+		const map: ImpactMap = { 'packages/cli/src/x.ts': { '10': ['tests/e2e/a.spec.ts'] } };
+		const mapFile = path.join(tempDir, 'map.json');
+		fs.writeFileSync(mapFile, JSON.stringify(map));
+		const allSpecsFile = path.join(tempDir, 'all-specs.txt');
+		fs.writeFileSync(allSpecsFile, ALL_SPECS.join('\n'));
+		const manifests = {
+			'package.json': {
+				before: JSON.stringify({ pnpm: { overrides: {} } }),
+				after: JSON.stringify({ pnpm: { overrides: { [`${target}@<2`]: '2.0.0' } } }),
+			},
+		};
+		return { mapFile, allSpecsFile, manifests };
+	};
+
+	it('target outside the runtime closure → scoped with no specs (skip)', () => {
+		const result = selectTests({
+			changedFiles,
+			...setup('@vitest/browser'),
+			runtimeClosure: new Set(['ajv', 'fast-uri']),
+		});
+		expect(result.mode).toBe('scoped');
+		expect(result.specs).toEqual([]);
+	});
+
+	it('target inside the runtime closure → broad', () => {
+		const result = selectTests({
+			changedFiles,
+			...setup('fast-uri'),
+			runtimeClosure: new Set(['ajv', 'fast-uri']),
+		});
+		expect(result.mode).toBe('broad');
+		expect(result.specs).toEqual([...ALL_SPECS].sort());
+	});
+
+	it('no runtime closure supplied → broad (cannot prove dev-only)', () => {
+		const result = selectTests({
+			changedFiles,
+			...setup('@vitest/browser'),
+		});
+		expect(result.mode).toBe('broad');
+	});
+});
diff --git a/packages/testing/test-impact/src/select.ts b/packages/testing/test-impact/src/select.ts
index 6de4797b72b..1861981330e 100644
--- a/packages/testing/test-impact/src/select.ts
+++ b/packages/testing/test-impact/src/select.ts
@@ -54,6 +54,10 @@ export interface SelectTestsInput {
 	 *  walked to its declaring packages and scoped via the map instead
 	 *  of forcing broad. */
 	lockfileImporters?: WorkspaceImporters;
+	/** Package names reachable from the deployed packages' runtime deps (see
+	 *  `runtimeClosure` in dep-graph). Classifies `pnpm.overrides` changes;
+	 *  omitted → an override change stays broad. */
+	runtimeClosure?: ReadonlySet<string>;
 }
 
 export interface SelectTestsResult extends ResolveResult {
@@ -127,8 +131,11 @@ export function selectTests(input: SelectTestsInput): SelectTestsResult {
 		impactful = impactful.filter((f) => !isTsconfig(f));
 	}
 
-	// devDependency-only change can't reach the runtime bundle → dropped.
-	if (input.manifests) impactful = dropDevDepOnlyDeps(impactful, input.manifests);
+	// devDependency-only change can't reach the runtime bundle → dropped. Same for
+	// a `pnpm.overrides` pin whose target is outside the runtime closure.
+	if (input.manifests) {
+		impactful = dropDevDepOnlyDeps(impactful, input.manifests, input.runtimeClosure);
+	}
 
 	// Runtime-dep change: walk it to the packages that declare it and drop
 	// the dep files from the coverage path.
@@ -160,7 +167,10 @@ export function selectTests(input: SelectTestsInput): SelectTestsResult {
 		if (!/(^|\/)package\.json$/.test(f)) return false;
 		const manifest = input.manifests?.[f];
 		if (!manifest) return true;
-		return classifyManifestChange(manifest.before, manifest.after) === 'runtime';
+		// An `override` still present here failed the closure check → unproven,
+		// treat like runtime.
+		const kind = classifyManifestChange(manifest.before, manifest.after);
+		return kind === 'runtime' || kind === 'override';
 	});
 	if (lockfileRemains || unscopedRuntimeManifest) return broad(impactful);