diff --git a/packages/@apphosting/adapter-angular/package.json b/packages/@apphosting/adapter-angular/package.json
index 2cdd1212..9374225b 100644
--- a/packages/@apphosting/adapter-angular/package.json
+++ b/packages/@apphosting/adapter-angular/package.json
@@ -23,7 +23,7 @@
   "scripts": {
     "build": "rm -rf dist && tsc && chmod +x ./dist/bin/*",
     "test": "npm run test:unit && npm run test:functional",
-    "test:unit": "ts-mocha -p tsconfig.json src/**/*.spec.ts",
+    "test:unit": "ts-mocha -p tsconfig.json 'src/**/*.spec.ts' 'src/*.spec.ts'",
     "test:functional": "node --loader ts-node/esm ./e2e/run-local.ts",
     "localregistry:start": "npx verdaccio --config ../publish-dev/verdaccio-config.yaml",
     "localregistry:publish": "(npm view --registry=http://localhost:4873 @apphosting/adapter-angular && npm unpublish --@apphosting:registry=http://localhost:4873 --force); npm publish --@apphosting:registry=http://localhost:4873"
diff --git a/packages/@apphosting/adapter-angular/src/bin/build.spec.ts b/packages/@apphosting/adapter-angular/src/bin/build.spec.ts
index 84e8a3a5..3156a59b 100644
--- a/packages/@apphosting/adapter-angular/src/bin/build.spec.ts
+++ b/packages/@apphosting/adapter-angular/src/bin/build.spec.ts
@@ -15,6 +15,7 @@ describe("build commands", () => {
     outputBundleOptions = {
       browserDirectory: resolve(tmpDir, "dist", "test", "browser"),
       bundleYamlPath: resolve(tmpDir, ".apphosting", "bundle.yaml"),
+      outputDirectoryBasePath: resolve(tmpDir, ".apphosting"),
       serverFilePath: resolve(tmpDir, "dist", "test", "server", "server.mjs"),
       needsServerGenerated: false,
     };
@@ -82,6 +83,7 @@ metadata:
     const expectedOutputBundleOptions = {
       browserDirectory: "/browser",
       bundleYamlPath: resolve(".apphosting", "bundle.yaml"),
+      outputDirectoryBasePath: resolve(".apphosting"),
       needsServerGenerated: false,
       serverFilePath: path.join("/server", "server.mjs"),
     };
diff --git a/packages/@apphosting/adapter-angular/src/bin/build.ts b/packages/@apphosting/adapter-angular/src/bin/build.ts
index 1a7b756e..0776a464 100644
--- a/packages/@apphosting/adapter-angular/src/bin/build.ts
+++ b/packages/@apphosting/adapter-angular/src/bin/build.ts
@@ -4,7 +4,7 @@ import {
   checkBuildConditions,
   validateOutputDirectory,
   parseOutputBundleOptions,
-  outputBundleExists,
+  metaFrameworkOutputBundleExists,
 } from "../utils.js";
 import { getBuildOptions, runBuild } from "@apphosting/common";
 
@@ -21,7 +21,11 @@ if (!output) {
 }
 
 const angularVersion = process.env.FRAMEWORK_VERSION || "unspecified";
-if (!outputBundleExists()) {
+// Frameworks like nitro, analog, nuxt generate the output bundle during their own build process
+// when `npm run build` is called which we don't want to overwrite immediately after.
+// We only want to overwrite if the existing output is from a previous framework adapter
+// build on a plain angular app.
+if (!metaFrameworkOutputBundleExists()) {
   const outputBundleOptions = parseOutputBundleOptions(output);
   const root = process.cwd();
   await generateBuildOutput(root, outputBundleOptions, angularVersion);
diff --git a/packages/@apphosting/adapter-angular/src/interface.ts b/packages/@apphosting/adapter-angular/src/interface.ts
index 355a6797..22f167b9 100644
--- a/packages/@apphosting/adapter-angular/src/interface.ts
+++ b/packages/@apphosting/adapter-angular/src/interface.ts
@@ -4,6 +4,7 @@ import { URL } from "node:url";
 // options to help generate output directory
 export interface OutputBundleOptions {
   bundleYamlPath: string;
+  outputDirectoryBasePath: string;
   serverFilePath: string;
   browserDirectory: string;
   needsServerGenerated: boolean;
diff --git a/packages/@apphosting/adapter-angular/src/utils.spec.ts b/packages/@apphosting/adapter-angular/src/utils.spec.ts
new file mode 100644
index 00000000..d3a88192
--- /dev/null
+++ b/packages/@apphosting/adapter-angular/src/utils.spec.ts
@@ -0,0 +1,69 @@
+const importUtils = import("@apphosting/adapter-angular/dist/utils.js");
+import assert from "assert";
+import fs from "fs";
+import * as path from "path";
+import { stringify as yamlStringify } from "yaml";
+import os from "os";
+import type { OutputBundleConfig } from "@apphosting/common";
+
+function generateTmpDir(): string {
+  return fs.mkdtempSync(path.join(os.tmpdir(), "test-files"));
+}
+
+describe("metaFrameworkOutputBundleExists", () => {
+  let bundlePath: string;
+  const originalCwd = process.cwd.bind(process);
+
+  beforeEach(() => {
+    const tmpDir = generateTmpDir();
+    process.cwd = () => tmpDir;
+    fs.mkdirSync(path.resolve(tmpDir, ".apphosting"));
+    bundlePath = path.resolve(tmpDir, ".apphosting", "bundle.yaml");
+  });
+
+  afterEach(() => {
+    process.cwd = originalCwd;
+  });
+
+  it("unrecognized bundle", async () => {
+    const { metaFrameworkOutputBundleExists } = await importUtils;
+    const content = "chicken: bok bok";
+    fs.writeFileSync(bundlePath, yamlStringify(content));
+    assert(!metaFrameworkOutputBundleExists());
+  });
+
+  it("no bundle exists", async () => {
+    const { metaFrameworkOutputBundleExists } = await importUtils;
+    assert(!metaFrameworkOutputBundleExists());
+  });
+
+  it("meta-framework bundle exists", async () => {
+    const { metaFrameworkOutputBundleExists } = await importUtils;
+    const outputBundle: OutputBundleConfig = {
+      version: "v1",
+      runConfig: {
+        runCommand: `does not matter`,
+      },
+      metadata: {
+        framework: "nitro",
+      },
+    };
+    fs.writeFileSync(bundlePath, yamlStringify(outputBundle));
+    assert(metaFrameworkOutputBundleExists());
+  });
+
+  it("angular bundle exists", async () => {
+    const { metaFrameworkOutputBundleExists } = await importUtils;
+    const outputBundle: OutputBundleConfig = {
+      version: "v1",
+      runConfig: {
+        runCommand: `does not matter`,
+      },
+      metadata: {
+        framework: "angular",
+      },
+    };
+    fs.writeFileSync(bundlePath, yamlStringify(outputBundle));
+    assert(!metaFrameworkOutputBundleExists());
+  });
+});
diff --git a/packages/@apphosting/adapter-angular/src/utils.ts b/packages/@apphosting/adapter-angular/src/utils.ts
index e5be7de1..6ce3bbd1 100644
--- a/packages/@apphosting/adapter-angular/src/utils.ts
+++ b/packages/@apphosting/adapter-angular/src/utils.ts
@@ -7,6 +7,7 @@ import { resolve, normalize, relative, dirname, join } from "path";
 import { stringify as yamlStringify } from "yaml";
 import { OutputBundleOptions, OutputPaths, buildManifestSchema } from "./interface.js";
 import { createRequire } from "node:module";
+import { parse as parseYaml } from "yaml";
 import stripAnsi from "strip-ansi";
 import {
   BuildOptions,
@@ -14,10 +15,12 @@ import {
   EnvVarConfig,
   Metadata,
   Availability,
+  updateOrCreateGitignore,
 } from "@apphosting/common";
 
 // fs-extra is CJS, readJson can't be imported using shorthand
-export const { writeFile, move, readJson, mkdir, copyFile, readFileSync, existsSync } = fsExtra;
+export const { writeFile, move, readJson, mkdir, copyFile, readFileSync, existsSync, ensureDir } =
+  fsExtra;
 
 const require = createRequire(import.meta.url);
 const __filename = fileURLToPath(import.meta.url);
@@ -135,6 +138,7 @@ export function populateOutputBundleOptions(outputPaths: OutputPaths): OutputBun
   }
   return {
     bundleYamlPath: resolve(outputBundleDir, "bundle.yaml"),
+    outputDirectoryBasePath: outputBundleDir,
     serverFilePath: resolve(baseDirectory, serverRelativePath, "server.mjs"),
     browserDirectory: resolve(baseDirectory, browserRelativePath),
     needsServerGenerated,
@@ -210,6 +214,10 @@ export async function generateBuildOutput(
     await generateServer(outputBundleOptions);
   }
   await generateBundleYaml(outputBundleOptions, cwd, angularVersion);
+  // generateBundleYaml creates the output directory (if it does not already exist).
+  // We need to make sure it is gitignored.
+  const normalizedBundleDir = normalize(relative(cwd, outputBundleOptions.outputDirectoryBasePath));
+  updateOrCreateGitignore(cwd, [`/${normalizedBundleDir}/`]);
 }
 
 // add environment variable to bundle.yaml if needed for specific versions
@@ -233,7 +241,7 @@ async function generateBundleYaml(
   cwd: string,
   angularVersion: string,
 ): Promise<void> {
-  await mkdir(dirname(opts.bundleYamlPath));
+  await ensureDir(dirname(opts.bundleYamlPath));
   const outputBundle: OutputBundleConfig = {
     version: "v1",
     runConfig: {
@@ -270,10 +278,18 @@ export const isMain = (meta: ImportMeta) => {
   return process.argv[1] === fileURLToPath(meta.url);
 };
 
-export const outputBundleExists = () => {
+export const metaFrameworkOutputBundleExists = () => {
   const outputBundleDir = resolve(".apphosting");
-  if (existsSync(outputBundleDir)) {
-    return true;
+  const bundleYamlPath = join(outputBundleDir, "bundle.yaml");
+  if (existsSync(bundleYamlPath)) {
+    try {
+      const bundle = parseYaml(readFileSync(bundleYamlPath, "utf8"));
+      if (bundle?.metadata?.framework && bundle.metadata.framework !== "angular") {
+        return true;
+      }
+    } catch (e) {
+      logger.debug("Failed to parse bundle.yaml, assuming it can be overwritten", e);
+    }
   }
   return false;
 };