diff --git a/scripts/openclaw-npm-postpublish-verify.ts b/scripts/openclaw-npm-postpublish-verify.ts
index 7fd04e41297..fce132b7167 100644
--- a/scripts/openclaw-npm-postpublish-verify.ts
+++ b/scripts/openclaw-npm-postpublish-verify.ts
@@ -41,6 +41,8 @@ type InstalledBundledExtensionManifestRecord = {
 };
 
 const MAX_BUNDLED_EXTENSION_MANIFEST_BYTES = 1024 * 1024;
+const LEGACY_CONTEXT_ENGINE_UNRESOLVED_RUNTIME_MARKER =
+  "Failed to load legacy context engine runtime.";
 const NPM_UPDATE_COMPAT_EXTENSION_DIRS = new Set(
   [...NPM_UPDATE_COMPAT_SIDECAR_PATHS].map((relativePath) => {
     const pathParts = relativePath.split("/");
@@ -101,6 +103,7 @@ export function collectInstalledPackageErrors(params: {
     }
   }
 
+  errors.push(...collectInstalledContextEngineRuntimeErrors(params.packageRoot));
   errors.push(...collectInstalledMirroredRootDependencyManifestErrors(params.packageRoot));
 
   return errors;
@@ -112,6 +115,48 @@ export function normalizeInstalledBinaryVersion(output: string): string {
   return versionMatch?.[0] ?? trimmed;
 }
 
+function listDistJavaScriptFiles(packageRoot: string): string[] {
+  const distDir = join(packageRoot, "dist");
+  if (!existsSync(distDir)) {
+    return [];
+  }
+
+  const pending = [distDir];
+  const files: string[] = [];
+  while (pending.length > 0) {
+    const currentDir = pending.pop();
+    if (!currentDir) {
+      continue;
+    }
+    for (const entry of readdirSync(currentDir, { withFileTypes: true })) {
+      const entryPath = join(currentDir, entry.name);
+      if (entry.isDirectory()) {
+        pending.push(entryPath);
+        continue;
+      }
+      if (entry.isFile() && entry.name.endsWith(".js")) {
+        files.push(entryPath);
+      }
+    }
+  }
+
+  return files;
+}
+
+export function collectInstalledContextEngineRuntimeErrors(packageRoot: string): string[] {
+  const errors: string[] = [];
+  for (const filePath of listDistJavaScriptFiles(packageRoot)) {
+    const contents = readFileSync(filePath, "utf8");
+    if (contents.includes(LEGACY_CONTEXT_ENGINE_UNRESOLVED_RUNTIME_MARKER)) {
+      errors.push(
+        "installed package includes unresolved legacy context engine runtime loader; rebuild with a bundler-traceable LegacyContextEngine import.",
+      );
+      break;
+    }
+  }
+  return errors;
+}
+
 export function resolveInstalledBinaryPath(prefixDir: string, platform = process.platform): string {
   return platform === "win32"
     ? join(prefixDir, "openclaw.cmd")
diff --git a/src/context-engine/legacy.registration.ts b/src/context-engine/legacy.registration.ts
index 3bd131114be..769681d33e5 100644
--- a/src/context-engine/legacy.registration.ts
+++ b/src/context-engine/legacy.registration.ts
@@ -1,32 +1,8 @@
+import { LegacyContextEngine } from "./legacy.js";
 import { registerContextEngineForOwner } from "./registry.js";
-import type { ContextEngine } from "./types.js";
-
-type LegacyContextEngineModule = {
-  LegacyContextEngine: new () => ContextEngine;
-};
-
-async function loadLegacyContextEngineModule(): Promise<LegacyContextEngineModule> {
-  try {
-    return (await import("./legacy.js")) as LegacyContextEngineModule;
-  } catch {
-    try {
-      return (await import("./legacy.ts")) as LegacyContextEngineModule;
-    } catch {
-      throw new Error("Failed to load legacy context engine runtime.");
-    }
-  }
-}
 
 export function registerLegacyContextEngine(): void {
-  registerContextEngineForOwner(
-    "legacy",
-    async () => {
-      const { LegacyContextEngine } = await loadLegacyContextEngineModule();
-      return new LegacyContextEngine();
-    },
-    "core",
-    {
-      allowSameOwnerRefresh: true,
-    },
-  );
+  registerContextEngineForOwner("legacy", async () => new LegacyContextEngine(), "core", {
+    allowSameOwnerRefresh: true,
+  });
 }
diff --git a/test/openclaw-npm-postpublish-verify.test.ts b/test/openclaw-npm-postpublish-verify.test.ts
index 61faa26eeb4..176448210bb 100644
--- a/test/openclaw-npm-postpublish-verify.test.ts
+++ b/test/openclaw-npm-postpublish-verify.test.ts
@@ -5,6 +5,7 @@ import { describe, expect, it } from "vitest";
 import {
   buildPublishedInstallCommandArgs,
   buildPublishedInstallScenarios,
+  collectInstalledContextEngineRuntimeErrors,
   collectInstalledMirroredRootDependencyManifestErrors,
   collectInstalledPackageErrors,
   normalizeInstalledBinaryVersion,
@@ -79,6 +80,48 @@ describe("collectInstalledPackageErrors", () => {
   });
 });
 
+describe("collectInstalledContextEngineRuntimeErrors", () => {
+  function makeInstalledPackageRoot(): string {
+    return mkdtempSync(join(tmpdir(), "openclaw-postpublish-context-engine-"));
+  }
+
+  it("rejects packaged bundles with unresolved legacy context engine runtime loaders", () => {
+    const packageRoot = makeInstalledPackageRoot();
+
+    try {
+      mkdirSync(join(packageRoot, "dist"), { recursive: true });
+      writeFileSync(
+        join(packageRoot, "dist", "runtime-plugins-BUG.js"),
+        'throw new Error("Failed to load legacy context engine runtime.");\n',
+        "utf8",
+      );
+
+      expect(collectInstalledContextEngineRuntimeErrors(packageRoot)).toEqual([
+        "installed package includes unresolved legacy context engine runtime loader; rebuild with a bundler-traceable LegacyContextEngine import.",
+      ]);
+    } finally {
+      rmSync(packageRoot, { recursive: true, force: true });
+    }
+  });
+
+  it("accepts packaged bundles that inline the legacy context engine registration", () => {
+    const packageRoot = makeInstalledPackageRoot();
+
+    try {
+      mkdirSync(join(packageRoot, "dist"), { recursive: true });
+      writeFileSync(
+        join(packageRoot, "dist", "runtime-plugins-OK.js"),
+        "registerContextEngineForOwner('legacy', async () => new LegacyContextEngine());\n",
+        "utf8",
+      );
+
+      expect(collectInstalledContextEngineRuntimeErrors(packageRoot)).toEqual([]);
+    } finally {
+      rmSync(packageRoot, { recursive: true, force: true });
+    }
+  });
+});
+
 describe("normalizeInstalledBinaryVersion", () => {
   it("accepts decorated CLI version output", () => {
     expect(normalizeInstalledBinaryVersion("OpenClaw 2026.4.8 (9ece252)")).toBe("2026.4.8");