diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 8a425a7..ea3891b 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -11,7 +11,8 @@ env:
   GITHUB_REF: '${{ github.ref }}'
   WINDOWS_TARGET: x86_64-pc-windows-msvc
   MACOS_TARGET: x86_64-apple-darwin
-  LINUX_TARGET: x86_64-unknown-linux-musl
+  LINUX_AMD64_TARGET: x86_64-unknown-linux-musl
+  LINUX_ARM64_TARGET: aarch64-unknown-linux-musl
 
   # Space separated paths to include in the archive.
   RELEASE_ADDS: README.md LICENSE-APACHE LICENSE-MIT
@@ -22,15 +23,17 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        build: [linux, macos, windows]
         include:
-          - build: linux
+          - target: x86_64-unknown-linux-musl
             os: ubuntu-latest
             rust: stable
-          - build: macos
+          - target: aarch64-unknown-linux-musl
+            os: ubuntu-latest
+            rust: stable
+          - target: x86_64-apple-darwin
             os: macos-latest
             rust: stable
-          - build: windows
+          - target: x86_64-pc-windows-msvc
             os: windows-latest
             rust: stable
 
@@ -49,67 +52,56 @@ jobs:
           echo "using version tag ${GITHUB_REF:10}"
           echo ::set-output name=version::"${GITHUB_REF:10}"
 
-      - name: Install musl-tools (Linux)
-        if: matrix.build == 'linux'
+      - name: Install C compilation tooling (Linux)
+        if: matrix.os == 'ubuntu-latest'
         run: |
           sudo apt-get update -y
-          sudo apt-get install musl-tools -y
+          sudo apt-get install clang gcc-aarch64-linux-gnu -y
+          echo "TARGET_CC=clang" >> $GITHUB_ENV
+          echo "CFLAGS_aarch64_unknown_linux_musl=--sysroot=/usr/aarch64-linux-gnu" >> $GITHUB_ENV
+          echo "CARGO_TARGET_AARCH64_UNKNOWN_LINUX_MUSL_LINKER=/usr/aarch64-linux-gnu/bin/ld" >> $GITHUB_ENV
 
       - name: Install p7zip (MacOS)
-        if: matrix.build == 'macos'
+        if: matrix.os == 'macos-latest'
         run: brew install p7zip
 
-      - name: Build (Linux)
-        if: matrix.build == 'linux'
-        run: |
-          rustup target add ${{ env.LINUX_TARGET }}
-          cargo build --release --target ${{ env.LINUX_TARGET }}
+      - name: Add rustup target
+        run: rustup target add ${{ matrix.target }}
 
-      - name: Build (MacOS)
-        if: matrix.build == 'macos'
-        run: cargo build --release
+      - name: Build
+        run: cargo build --release --target ${{ matrix.target }}
 
-      - name: Build (Windows)
-        if: matrix.build == 'windows'
-        run: cargo build --release
-        env:
-          RUSTFLAGS: -Ctarget-feature=+crt-static
+      - name: Set RUSTFLAGS (Windows)
+        if: matrix.os == 'windows-latest'
+        run: echo "RUSTFLAGS=-Ctarget-feature=+crt-static" >> $GITHUB_ENV
 
       - name: Create artifact directory
         run: |
           mkdir ${{ env.RELEASE_DIR }}
-          mkdir -p ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}
-          mkdir -p ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}
-          mkdir -p ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}
+          mkdir -p ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}
 
-      - name: Create tarball (Linux)
-        if: matrix.build == 'linux'
+      - name: Move binaries (Linux/MacOS)
+        if: matrix.os == 'ubuntu-latest' || matrix.os == 'macos-latest'
         run: |
-          mv ./target/${{ env.LINUX_TARGET }}/release/${{ env.RELEASE_BIN }} ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}/${{ env.RELEASE_BIN }}
-          mv ${{ env.RELEASE_ADDS }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}
-          7z a -ttar -so -an ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }} | 7z a -si ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}.tar.gz
+          mv ./target/${{ matrix.target }}/release/${{ env.RELEASE_BIN }} ${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}/${{ env.RELEASE_BIN }}
+          mv ${{ env.RELEASE_ADDS }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}
 
-      - name: Create tarball (Windows)
-        if: matrix.build == 'windows'
+      - name: Move binaries (Windows)
+        if: matrix.os == 'windows-latest'
         shell: bash
         run: |
-          cp ./target/release/${{ env.RELEASE_BIN }}.exe ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}/${{ env.RELEASE_BIN }}.exe
-          cp ./target/release/${{ env.RELEASE_BIN }}.exe wasm-pack-init.exe
-          mv ${{ env.RELEASE_ADDS }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}
+          cp ./target/${{ matrix.target }}/release/${{ env.RELEASE_BIN }}.exe ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}/${{ env.RELEASE_BIN }}.exe
+          cp ./target/${{ matrix.target }}/release/${{ env.RELEASE_BIN }}.exe wasm-pack-init.exe
+          mv ${{ env.RELEASE_ADDS }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}
           mv wasm-pack-init.exe ${{ env.RELEASE_DIR }}
-          7z a -ttar -so -an ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }} | 7z a -si ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}.tar.gz
 
-      - name: Create tarball (MacOS)
-        if: matrix.build == 'macos'
-        run: |
-          mv ./target/release/${{ env.RELEASE_BIN }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}/${{ env.RELEASE_BIN }}
-          mv ${{ env.RELEASE_ADDS }} ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}
-          7z a -ttar -so -an ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }} | 7z a -si ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}.tar.gz
+      - name: Create tarball
+        run: 7z a -ttar -so -an ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }} | 7z a -si ./${{ env.RELEASE_DIR }}/${{ env.RELEASE_BIN }}-${{ steps.get_version.outputs.VERSION }}-${{ matrix.target }}.tar.gz
 
       - name: Upload Zip
         uses: actions/upload-artifact@v1
         with:
-          name: ${{ matrix.build }}
+          name: ${{ matrix.target }}
           path: ./${{ env.RELEASE_DIR }}
 
   release:
@@ -133,30 +125,45 @@ jobs:
           tag_name: ${{ steps.get_version.outputs.VERSION }}
           release_name: ${{ steps.get_version.outputs.VERSION }}
 
-      - name: Download Linux tarball
-        uses: actions/download-artifact@v1
+      - name: Download Linux amd64 tarball
+        uses: actions/download-artifact@v2
+        with:
+          name: ${{ env.LINUX_AMD64_TARGET }}
+
+      - name: Download Linux arm64 tarball
+        uses: actions/download-artifact@v2
         with:
-          name: linux
+          name: ${{ env.LINUX_ARM64_TARGET }}
 
       - name: Download Windows tarball
-        uses: actions/download-artifact@v1
+        uses: actions/download-artifact@v2
         with:
-          name: windows
+          name: ${{ env.WINDOWS_TARGET }}
 
       - name: Download MacOS tarball
-        uses: actions/download-artifact@v1
+        uses: actions/download-artifact@v2
         with:
-          name: macos
+          name: ${{ env.MACOS_TARGET }}
+
+      - name: Release Linux amd64 tarball
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: ./wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_AMD64_TARGET }}.tar.gz
+          asset_content_type: application/gzip
+          asset_name: wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_AMD64_TARGET }}.tar.gz
 
-      - name: Release Linux tarball
+      - name: Release Linux arm64 tarball
         uses: actions/upload-release-asset@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: ./linux/wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}.tar.gz
+          asset_path: ./wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_ARM64_TARGET }}.tar.gz
           asset_content_type: application/gzip
-          asset_name: wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_TARGET }}.tar.gz
+          asset_name: wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.LINUX_ARM64_TARGET }}.tar.gz
 
       - name: Release Windows tarball
         uses: actions/upload-release-asset@v1
@@ -164,7 +171,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: ./windows/wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}.tar.gz
+          asset_path: ./wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}.tar.gz
           asset_content_type: application/gzip
           asset_name: wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.WINDOWS_TARGET }}.tar.gz
 
@@ -174,7 +181,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: ./windows/wasm-pack-init.exe
+          asset_path: ./wasm-pack-init.exe
           asset_content_type: application/vnd.microsoft.portable-executable
           asset_name: wasm-pack-init.exe
 
@@ -184,6 +191,6 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
-          asset_path: ./macos/wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}.tar.gz
+          asset_path: ./wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}.tar.gz
           asset_content_type: application/gzip
           asset_name: wasm-pack-${{ steps.get_version.outputs.VERSION }}-${{ env.MACOS_TARGET }}.tar.gz
diff --git a/src/command/utils.rs b/src/command/utils.rs
index 4a735e2..7c6ec0c 100644
--- a/src/command/utils.rs
+++ b/src/command/utils.rs
@@ -37,6 +37,7 @@ fn find_manifest_from_cwd() -> Result<PathBuf, failure::Error> {
 
 /// Construct our `pkg` directory in the crate.
 pub fn create_pkg_dir(out_dir: &Path) -> Result<(), failure::Error> {
+    let _ = fs::remove_dir_all(&out_dir); // Clean up any existing directory and ignore errors
     fs::create_dir_all(&out_dir)?;
     fs::write(out_dir.join(".gitignore"), "*")?;
     Ok(())
diff --git a/src/manifest/mod.rs b/src/manifest/mod.rs
index 3bd9249..7682b42 100644
--- a/src/manifest/mod.rs
+++ b/src/manifest/mod.rs
@@ -8,8 +8,8 @@
 
 mod npm;
 
-use std::fs;
 use std::path::Path;
+use std::{collections::HashMap, fs};
 
 use self::npm::{
     repository::Repository, CommonJSPackage, ESModulesPackage, NoModulesPackage, NpmPackage,
@@ -575,14 +575,25 @@ impl CrateData {
         target: Target,
     ) -> Result<(), Error> {
         let pkg_file_path = out_dir.join("package.json");
+        // Check if a `package.json` was already generated by wasm-bindgen, if so
+        // we merge the NPM dependencies already specified in it.
+        let existing_deps = if pkg_file_path.exists() {
+            // It's just a map of dependency names to versions
+            Some(serde_json::from_str::<HashMap<String, String>>(
+                &fs::read_to_string(&pkg_file_path)?,
+            )?)
+        } else {
+            None
+        };
         let npm_data = match target {
-            Target::Nodejs => self.to_commonjs(scope, disable_dts, out_dir),
-            Target::NoModules => self.to_nomodules(scope, disable_dts, out_dir),
-            Target::Bundler => self.to_esmodules(scope, disable_dts, out_dir),
-            Target::Web => self.to_web(scope, disable_dts, out_dir),
+            Target::Nodejs => self.to_commonjs(scope, disable_dts, existing_deps, out_dir),
+            Target::NoModules => self.to_nomodules(scope, disable_dts, existing_deps, out_dir),
+            Target::Bundler => self.to_esmodules(scope, disable_dts, existing_deps, out_dir),
+            Target::Web => self.to_web(scope, disable_dts, existing_deps, out_dir),
         };
 
         let npm_json = serde_json::to_string_pretty(&npm_data)?;
+
         fs::write(&pkg_file_path, npm_json)
             .with_context(|_| format!("failed to write: {}", pkg_file_path.display()))?;
         Ok(())
@@ -657,7 +668,13 @@ impl CrateData {
         })
     }
 
-    fn to_commonjs(&self, scope: &Option<String>, disable_dts: bool, out_dir: &Path) -> NpmPackage {
+    fn to_commonjs(
+        &self,
+        scope: &Option<String>,
+        disable_dts: bool,
+        dependencies: Option<HashMap<String, String>>,
+        out_dir: &Path,
+    ) -> NpmPackage {
         let data = self.npm_data(scope, false, disable_dts, out_dir);
         let pkg = &self.data.packages[self.current_idx];
 
@@ -683,6 +700,7 @@ impl CrateData {
             homepage: data.homepage,
             types: data.dts_file,
             keywords: data.keywords,
+            dependencies,
         })
     }
 
@@ -690,6 +708,7 @@ impl CrateData {
         &self,
         scope: &Option<String>,
         disable_dts: bool,
+        dependencies: Option<HashMap<String, String>>,
         out_dir: &Path,
     ) -> NpmPackage {
         let data = self.npm_data(scope, true, disable_dts, out_dir);
@@ -719,10 +738,17 @@ impl CrateData {
             types: data.dts_file,
             side_effects: false,
             keywords: data.keywords,
+            dependencies,
         })
     }
 
-    fn to_web(&self, scope: &Option<String>, disable_dts: bool, out_dir: &Path) -> NpmPackage {
+    fn to_web(
+        &self,
+        scope: &Option<String>,
+        disable_dts: bool,
+        dependencies: Option<HashMap<String, String>>,
+        out_dir: &Path,
+    ) -> NpmPackage {
         let data = self.npm_data(scope, false, disable_dts, out_dir);
         let pkg = &self.data.packages[self.current_idx];
 
@@ -750,6 +776,7 @@ impl CrateData {
             types: data.dts_file,
             side_effects: false,
             keywords: data.keywords,
+            dependencies,
         })
     }
 
@@ -757,6 +784,7 @@ impl CrateData {
         &self,
         scope: &Option<String>,
         disable_dts: bool,
+        dependencies: Option<HashMap<String, String>>,
         out_dir: &Path,
     ) -> NpmPackage {
         let data = self.npm_data(scope, false, disable_dts, out_dir);
@@ -784,6 +812,7 @@ impl CrateData {
             homepage: data.homepage,
             types: data.dts_file,
             keywords: data.keywords,
+            dependencies,
         })
     }
 
diff --git a/src/manifest/npm/commonjs.rs b/src/manifest/npm/commonjs.rs
index e421c9c..eaf681d 100644
--- a/src/manifest/npm/commonjs.rs
+++ b/src/manifest/npm/commonjs.rs
@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use manifest::npm::repository::Repository;
 
 #[derive(Serialize)]
@@ -21,4 +23,6 @@ pub struct CommonJSPackage {
     pub types: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub keywords: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub dependencies: Option<HashMap<String, String>>,
 }
diff --git a/src/manifest/npm/esmodules.rs b/src/manifest/npm/esmodules.rs
index 68d2174..837f07e 100644
--- a/src/manifest/npm/esmodules.rs
+++ b/src/manifest/npm/esmodules.rs
@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use manifest::npm::repository::Repository;
 
 #[derive(Serialize)]
@@ -25,4 +27,6 @@ pub struct ESModulesPackage {
     pub side_effects: bool,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub keywords: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub dependencies: Option<HashMap<String, String>>,
 }
diff --git a/src/manifest/npm/nomodules.rs b/src/manifest/npm/nomodules.rs
index 6ac2508..20567cc 100644
--- a/src/manifest/npm/nomodules.rs
+++ b/src/manifest/npm/nomodules.rs
@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use manifest::npm::repository::Repository;
 
 #[derive(Serialize)]
@@ -21,4 +23,6 @@ pub struct NoModulesPackage {
     pub types: Option<String>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub keywords: Option<Vec<String>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub dependencies: Option<HashMap<String, String>>,
 }
diff --git a/tests/all/manifest.rs b/tests/all/manifest.rs
index f7cf57a..78fdc6a 100644
--- a/tests/all/manifest.rs
+++ b/tests/all/manifest.rs
@@ -1,5 +1,5 @@
 use assert_cmd::prelude::*;
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 use std::fs;
 use std::path::PathBuf;
 use utils::{self, fixture};
@@ -319,6 +319,54 @@ fn it_creates_a_package_json_with_correct_keys_when_types_are_skipped() {
     assert_eq!(actual_files, expected_files);
 }
 
+#[test]
+fn it_creates_a_package_json_with_npm_dependencies_provided_by_wasm_bindgen() {
+    let fixture = fixture::js_hello_world();
+    let out_dir = fixture.path.join("pkg");
+    let crate_data = manifest::CrateData::new(&fixture.path, None).unwrap();
+    wasm_pack::command::utils::create_pkg_dir(&out_dir).unwrap();
+    // Write a `package.json` in the out_dir, as wasm-bindgen does:
+    utils::manifest::create_wbg_package_json(
+        &out_dir,
+        r#"
+        { "foo": "^1.2.3" }
+    "#,
+    )
+    .unwrap();
+    assert!(crate_data
+        .write_package_json(&out_dir, &None, true, Target::Bundler)
+        .is_ok());
+    let package_json_path = &out_dir.join("package.json");
+    fs::metadata(package_json_path).unwrap();
+    utils::manifest::read_package_json(&fixture.path, &out_dir).unwrap();
+    let pkg = utils::manifest::read_package_json(&fixture.path, &out_dir).unwrap();
+    assert_eq!(pkg.name, "js-hello-world");
+    assert_eq!(pkg.repository.ty, "git");
+    assert_eq!(
+        pkg.repository.url,
+        "https://github.com/rustwasm/wasm-pack.git"
+    );
+    assert_eq!(pkg.module, "js_hello_world.js");
+
+    let actual_files: HashSet<String> = pkg.files.into_iter().collect();
+    let expected_files: HashSet<String> = [
+        "js_hello_world_bg.wasm",
+        "js_hello_world_bg.js",
+        "js_hello_world.js",
+    ]
+    .iter()
+    .map(|&s| String::from(s))
+    .collect();
+    assert_eq!(actual_files, expected_files);
+
+    let dependencies: Option<HashMap<String, String>> = pkg.dependencies;
+    assert!(dependencies.is_some());
+    let mut expected_dependencies: HashMap<String, String> = HashMap::new();
+    expected_dependencies.insert("foo".to_owned(), "^1.2.3".to_owned());
+
+    assert_eq!(dependencies.unwrap(), expected_dependencies);
+}
+
 #[test]
 fn it_errors_when_wasm_bindgen_is_not_declared() {
     let fixture = fixture::bad_cargo_toml();
diff --git a/tests/all/utils/manifest.rs b/tests/all/utils/manifest.rs
index da5d2ea..4b911ba 100644
--- a/tests/all/utils/manifest.rs
+++ b/tests/all/utils/manifest.rs
@@ -1,6 +1,6 @@
-use std::fs::File;
 use std::io::prelude::*;
 use std::path::Path;
+use std::{collections::HashMap, fs::File};
 
 use failure::Error;
 use serde_json;
@@ -27,6 +27,7 @@ pub struct NpmPackage {
     pub side_effects: bool,
     pub homepage: Option<String>,
     pub keywords: Option<Vec<String>>,
+    pub dependencies: Option<HashMap<String, String>>,
 }
 
 fn default_none() -> String {
@@ -52,3 +53,8 @@ pub fn read_package_json(path: &Path, out_dir: &Path) -> Result<NpmPackage, Erro
 
     Ok(serde_json::from_str(&pkg_contents)?)
 }
+
+pub fn create_wbg_package_json(out_dir: &Path, contents: &str) -> Result<(), Error> {
+    let manifest_path = out_dir.join("package.json");
+    Ok(std::fs::write(manifest_path, contents)?)
+}