diff --git a/packages/cli/index.ts b/packages/cli/index.ts
index d857831fb7..b1af282ce4 100644
--- a/packages/cli/index.ts
+++ b/packages/cli/index.ts
@@ -9,6 +9,7 @@
 import { spawn } from 'node:child_process';
 import os from 'node:os';
 import v8 from 'node:v8';
+import { buildRelaunchSpawnSpec } from './src/utils/relaunchSpawnSpec.js';
 
 // --- Global Entry Point ---
 
@@ -74,17 +75,14 @@ async function run() {
     // --- Lightweight Parent Process / Daemon ---
     // We avoid importing heavy dependencies here to save ~1.5s of startup time.
 
-    const nodeArgs: string[] = [...process.execArgv];
-    const scriptArgs = process.argv.slice(2);
-
     const memoryArgs = await getMemoryNodeArgs();
-    nodeArgs.push(...memoryArgs);
-
-    const script = process.argv[1];
-    nodeArgs.push(script);
-    nodeArgs.push(...scriptArgs);
-
-    const newEnv = { ...process.env, GEMINI_CLI_NO_RELAUNCH: 'true' };
+    const { args: relaunchArgs, env: newEnv } = buildRelaunchSpawnSpec({
+      additionalNodeArgs: memoryArgs,
+      additionalScriptArgs: [],
+      argv: process.argv,
+      env: process.env,
+      execArgv: process.execArgv,
+    });
     const RELAUNCH_EXIT_CODE = 199;
     let latestAdminSettings: unknown = undefined;
 
@@ -97,7 +95,7 @@ async function run() {
     const runner = () => {
       process.stdin.pause();
 
-      const child = spawn(process.execPath, nodeArgs, {
+      const child = spawn(process.execPath, relaunchArgs, {
         stdio: ['inherit', 'inherit', 'inherit', 'ipc'],
         env: newEnv,
       });
diff --git a/packages/cli/src/utils/relaunch.ts b/packages/cli/src/utils/relaunch.ts
index 7e287e4565..77b8dadda9 100644
--- a/packages/cli/src/utils/relaunch.ts
+++ b/packages/cli/src/utils/relaunch.ts
@@ -10,6 +10,7 @@ import {
   writeToStderr,
   type AdminControlsSettings,
 } from '@google/gemini-cli-core';
+import { buildRelaunchSpawnSpec } from './relaunchSpawnSpec.js';
 
 export async function relaunchOnExitCode(runner: () => Promise<number>) {
   while (true) {
@@ -43,19 +44,13 @@ export async function relaunchAppInChildProcess(
   let latestAdminSettings = remoteAdminSettings;
 
   const runner = () => {
-    // process.argv is [node, script, ...args]
-    // We want to construct [ ...nodeArgs, script, ...scriptArgs]
-    const script = process.argv[1];
-    const scriptArgs = process.argv.slice(2);
-
-    const nodeArgs = [
-      ...process.execArgv,
-      ...additionalNodeArgs,
-      script,
-      ...additionalScriptArgs,
-      ...scriptArgs,
-    ];
-    const newEnv = { ...process.env, GEMINI_CLI_NO_RELAUNCH: 'true' };
+    const { args: nodeArgs, env: newEnv } = buildRelaunchSpawnSpec({
+      additionalNodeArgs,
+      additionalScriptArgs,
+      argv: process.argv,
+      env: process.env,
+      execArgv: process.execArgv,
+    });
 
     // The parent process should not be reading from stdin while the child is running.
     process.stdin.pause();
diff --git a/packages/cli/src/utils/relaunchSpawnSpec.test.ts b/packages/cli/src/utils/relaunchSpawnSpec.test.ts
new file mode 100644
index 0000000000..6b30aed286
--- /dev/null
+++ b/packages/cli/src/utils/relaunchSpawnSpec.test.ts
@@ -0,0 +1,57 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, expect, it } from 'vitest';
+import { buildRelaunchSpawnSpec } from './relaunchSpawnSpec.js';
+
+describe('buildRelaunchSpawnSpec', () => {
+  it('preserves node-style relaunch arguments for source installs', () => {
+    const { args, env } = buildRelaunchSpawnSpec({
+      additionalNodeArgs: ['--max-old-space-size=4096'],
+      additionalScriptArgs: ['--model', 'gemini-2.5-pro'],
+      argv: ['/usr/bin/node', '/app/cli.js', 'command', '--verbose'],
+      env: { PATH: '/usr/bin' },
+      execArgv: ['--inspect=9229'],
+    });
+
+    expect(args).toEqual([
+      '--inspect=9229',
+      '--max-old-space-size=4096',
+      '/app/cli.js',
+      '--model',
+      'gemini-2.5-pro',
+      'command',
+      '--verbose',
+    ]);
+    expect(env).toMatchObject({
+      GEMINI_CLI_NO_RELAUNCH: 'true',
+      PATH: '/usr/bin',
+    });
+    expect(env['NODE_OPTIONS']).toBeUndefined();
+  });
+
+  it('moves node flags into NODE_OPTIONS for standalone binaries', () => {
+    const { args, env } = buildRelaunchSpawnSpec({
+      additionalNodeArgs: ['--max-old-space-size=4096'],
+      additionalScriptArgs: ['--model', 'gemini-2.5-pro'],
+      argv: ['/tmp/gemini', '/tmp/gemini', '--verbose'],
+      env: {
+        IS_BINARY: 'true',
+        NODE_OPTIONS: '--trace-warnings',
+        PATH: '/usr/bin',
+      },
+      execArgv: ['--inspect=9229'],
+    });
+
+    expect(args).toEqual(['--model', 'gemini-2.5-pro', '--verbose']);
+    expect(env).toMatchObject({
+      GEMINI_CLI_NO_RELAUNCH: 'true',
+      IS_BINARY: 'true',
+      NODE_OPTIONS: '--trace-warnings --max-old-space-size=4096',
+      PATH: '/usr/bin',
+    });
+  });
+});
diff --git a/packages/cli/src/utils/relaunchSpawnSpec.ts b/packages/cli/src/utils/relaunchSpawnSpec.ts
new file mode 100644
index 0000000000..3b6a23afbd
--- /dev/null
+++ b/packages/cli/src/utils/relaunchSpawnSpec.ts
@@ -0,0 +1,58 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+export interface BuildRelaunchSpawnSpecParams {
+  additionalNodeArgs: string[];
+  additionalScriptArgs: string[];
+  argv: string[];
+  env: NodeJS.ProcessEnv;
+  execArgv: string[];
+}
+
+export interface RelaunchSpawnSpec {
+  args: string[];
+  env: NodeJS.ProcessEnv;
+}
+
+export function buildRelaunchSpawnSpec({
+  additionalNodeArgs,
+  additionalScriptArgs,
+  argv,
+  env,
+  execArgv,
+}: BuildRelaunchSpawnSpecParams): RelaunchSpawnSpec {
+  const scriptArgs = argv.slice(2);
+  const newEnv: NodeJS.ProcessEnv = {
+    ...env,
+    GEMINI_CLI_NO_RELAUNCH: 'true',
+  };
+
+  if (env['IS_BINARY'] === 'true') {
+    if (additionalNodeArgs.length > 0) {
+      newEnv['NODE_OPTIONS'] = [newEnv['NODE_OPTIONS'], ...additionalNodeArgs]
+        .filter(Boolean)
+        .join(' ');
+    }
+
+    return {
+      args: [...additionalScriptArgs, ...scriptArgs],
+      env: newEnv,
+    };
+  }
+
+  const script = argv[1];
+
+  return {
+    args: [
+      ...execArgv,
+      ...additionalNodeArgs,
+      script,
+      ...additionalScriptArgs,
+      ...scriptArgs,
+    ],
+    env: newEnv,
+  };
+}