diff --git a/src/bindgen.rs b/src/bindgen.rs
index 3bc2946d..d48887f2 100644
--- a/src/bindgen.rs
+++ b/src/bindgen.rs
@@ -189,6 +189,7 @@ pub fn wasm_bindgen_build(
     };
 
     let out_dir = out_dir.to_str().unwrap();
+    let out_name = &[data.crate_name(), target.to_owned()].join("_");
 
     let wasm_path = data
         .target_directory()
@@ -212,6 +213,8 @@ pub fn wasm_bindgen_build(
     cmd.arg(&wasm_path)
         .arg("--out-dir")
         .arg(out_dir)
+        .arg("--out-name")
+        .arg(out_name)
         .arg(dts_arg)
         .arg(target_arg);
 
diff --git a/src/command/build.rs b/src/command/build.rs
index c6bad240..c1d79321 100644
--- a/src/command/build.rs
+++ b/src/command/build.rs
@@ -25,7 +25,7 @@ pub struct Build {
     pub crate_data: manifest::CrateData,
     pub scope: Option<String>,
     pub disable_dts: bool,
-    pub target: String,
+    pub targets: Vec<String>,
     pub profile: BuildProfile,
     pub mode: BuildMode,
     pub out_dir: PathBuf,
@@ -99,7 +99,7 @@ pub struct BuildOptions {
 
     #[structopt(long = "target", short = "t", default_value = "browser")]
     /// Sets the target environment. [possible values: browser, nodejs, no-modules]
-    pub target: String,
+    pub target: Vec<String>,
 
     #[structopt(long = "debug")]
     /// Deprecated. Renamed to `--dev`.
@@ -134,7 +134,7 @@ impl Default for BuildOptions {
             scope: None,
             mode: BuildMode::Normal,
             disable_dts: false,
-            target: String::new(),
+            target: vec![],
             debug: false,
             dev: false,
             release: false,
@@ -166,8 +166,10 @@ impl Build {
 
         // `possible_values` in clap isn't supported by `structopt`
         let possible_targets = ["browser", "nodejs", "no-modules"];
-        if !possible_targets.contains(&build_opts.target.as_str()) {
-            bail!("Supported targets: browser, nodejs, no-modules");
+        for target in &build_opts.target {
+            if !possible_targets.contains(&target.as_str()) {
+                bail!("Supported targets: browser, nodejs, no-modules");
+            }
         }
 
         Ok(Build {
@@ -175,7 +177,7 @@ impl Build {
             crate_data,
             scope: build_opts.scope,
             disable_dts: build_opts.disable_dts,
-            target: build_opts.target,
+            targets: build_opts.target,
             profile,
             mode: build_opts.mode,
             out_dir,
@@ -315,7 +317,7 @@ impl Build {
             &self.out_dir,
             &self.scope,
             self.disable_dts,
-            &self.target,
+            &self.targets.iter().map(|n| n.as_ref()).collect::<Vec<_>>(),
             step,
         )?;
         info!(
@@ -358,15 +360,17 @@ impl Build {
 
     fn step_run_wasm_bindgen(&mut self, step: &Step) -> Result<(), Error> {
         info!("Building the wasm bindings...");
-        bindgen::wasm_bindgen_build(
-            &self.crate_data,
-            self.bindgen.as_ref().unwrap(),
-            &self.out_dir,
-            self.disable_dts,
-            &self.target,
-            self.profile,
-            step,
-        )?;
+        for target in &self.targets {
+            bindgen::wasm_bindgen_build(
+                &self.crate_data,
+                self.bindgen.as_ref().unwrap(),
+                &self.out_dir,
+                self.disable_dts,
+                target,
+                self.profile,
+                step,
+            )?;
+        }
         info!("wasm bindings were built at {:#?}.", &self.out_dir);
         Ok(())
     }
diff --git a/src/command/publish/mod.rs b/src/command/publish/mod.rs
index 568104b4..5e16b1f8 100644
--- a/src/command/publish/mod.rs
+++ b/src/command/publish/mod.rs
@@ -47,7 +47,7 @@ pub fn publish(
                     .to_string();
                 let build_opts = BuildOptions {
                     path: Some(crate_path.clone()),
-                    target,
+                    target: vec![target],
                     out_dir: out_dir.clone(),
                     ..Default::default()
                 };
diff --git a/src/manifest/mod.rs b/src/manifest/mod.rs
index 92f03cd4..ea9a0c56 100644
--- a/src/manifest/mod.rs
+++ b/src/manifest/mod.rs
@@ -5,9 +5,7 @@ mod npm;
 use std::fs;
 use std::path::Path;
 
-use self::npm::{
-    repository::Repository, CommonJSPackage, ESModulesPackage, NoModulesPackage, NpmPackage,
-};
+use self::npm::NpmPackage;
 use cargo_metadata::Metadata;
 use command::build::BuildProfile;
 use emoji;
@@ -366,22 +364,32 @@ impl CrateData {
         out_dir: &Path,
         scope: &Option<String>,
         disable_dts: bool,
-        target: &str,
+        targets: &[&str],
         step: &Step,
     ) -> Result<(), Error> {
         let msg = format!("{}Writing a package.json...", emoji::MEMO);
 
         PBAR.step(step, &msg);
         let pkg_file_path = out_dir.join("package.json");
-        let npm_data = if target == "nodejs" {
-            self.to_commonjs(scope, disable_dts)
-        } else if target == "no-modules" {
-            self.to_nomodules(scope, disable_dts)
-        } else {
-            self.to_esmodules(scope, disable_dts)
-        };
+        let mut npm_package = self.to_base_package(scope, disable_dts, targets[0]);
+        for target in targets {
+            if target == &"nodejs" {
+                let mut npm_data = self.npm_data(scope, false, disable_dts, target);
+                npm_package.main = Some(npm_data.main);
+                npm_package.files.append(&mut npm_data.files);
+            } else if target == &"no-modules" {
+                let mut npm_data = self.npm_data(scope, false, disable_dts, target);
+                npm_package.browser = Some(npm_data.main.clone());
+                npm_package.files.append(&mut npm_data.files);
+            } else {
+                let mut npm_data = self.npm_data(scope, false, disable_dts, target);
+                npm_package.module = Some(npm_data.main.clone());
+                npm_package.side_effects = Some("false".to_string());
+                npm_package.files.append(&mut npm_data.files);
+            }
+        }
 
-        let npm_json = serde_json::to_string_pretty(&npm_data)?;
+        let npm_json = serde_json::to_string_pretty(&npm_package)?;
         fs::write(&pkg_file_path, npm_json)
             .with_context(|_| format!("failed to write: {}", pkg_file_path.display()))?;
         Ok(())
@@ -392,15 +400,16 @@ impl CrateData {
         scope: &Option<String>,
         include_commonjs_shim: bool,
         disable_dts: bool,
+        target: &str,
     ) -> NpmData {
         let crate_name = self.crate_name();
-        let wasm_file = format!("{}_bg.wasm", crate_name);
-        let js_file = format!("{}.js", crate_name);
+        let wasm_file = format!("{}_{}_bg.wasm", crate_name, target);
+        let js_file = format!("{}_{}.js", crate_name, target);
         let mut files = vec![wasm_file];
 
         files.push(js_file.clone());
         if include_commonjs_shim {
-            let js_bg_file = format!("{}_bg.js", crate_name);
+            let js_bg_file = format!("{}_{}_bg.js", crate_name, target);
             files.push(js_bg_file.to_string());
         }
 
@@ -411,7 +420,7 @@ impl CrateData {
         };
 
         let dts_file = if !disable_dts {
-            let file = format!("{}.d.ts", crate_name);
+            let file = format!("{}_{}.d.ts", crate_name, target);
             files.push(file.to_string());
             Some(file)
         } else {
@@ -425,86 +434,18 @@ impl CrateData {
         }
     }
 
-    fn to_commonjs(&self, scope: &Option<String>, disable_dts: bool) -> NpmPackage {
-        let data = self.npm_data(scope, true, disable_dts);
-        let pkg = &self.data.packages[self.current_idx];
-
-        self.check_optional_fields();
-
-        NpmPackage::CommonJSPackage(CommonJSPackage {
-            name: data.name,
-            collaborators: pkg.authors.clone(),
-            description: self.manifest.package.description.clone(),
-            version: pkg.version.clone(),
-            license: self.manifest.package.license.clone(),
-            repository: self
-                .manifest
-                .package
-                .repository
-                .clone()
-                .map(|repo_url| Repository {
-                    ty: "git".to_string(),
-                    url: repo_url,
-                }),
-            files: data.files,
-            main: data.main,
-            types: data.dts_file,
-        })
-    }
-
-    fn to_esmodules(&self, scope: &Option<String>, disable_dts: bool) -> NpmPackage {
-        let data = self.npm_data(scope, false, disable_dts);
-        let pkg = &self.data.packages[self.current_idx];
-
-        self.check_optional_fields();
-
-        NpmPackage::ESModulesPackage(ESModulesPackage {
-            name: data.name,
-            collaborators: pkg.authors.clone(),
-            description: self.manifest.package.description.clone(),
-            version: pkg.version.clone(),
-            license: self.manifest.package.license.clone(),
-            repository: self
-                .manifest
-                .package
-                .repository
-                .clone()
-                .map(|repo_url| Repository {
-                    ty: "git".to_string(),
-                    url: repo_url,
-                }),
-            files: data.files,
-            module: data.main,
-            types: data.dts_file,
-            side_effects: "false".to_string(),
-        })
-    }
-
-    fn to_nomodules(&self, scope: &Option<String>, disable_dts: bool) -> NpmPackage {
-        let data = self.npm_data(scope, false, disable_dts);
+    fn to_base_package(
+        &self,
+        scope: &Option<String>,
+        disable_dts: bool,
+        target: &str,
+    ) -> NpmPackage {
+        let data = self.npm_data(scope, false, disable_dts, target);
         let pkg = &self.data.packages[self.current_idx];
 
         self.check_optional_fields();
 
-        NpmPackage::NoModulesPackage(NoModulesPackage {
-            name: data.name,
-            collaborators: pkg.authors.clone(),
-            description: self.manifest.package.description.clone(),
-            version: pkg.version.clone(),
-            license: self.manifest.package.license.clone(),
-            repository: self
-                .manifest
-                .package
-                .repository
-                .clone()
-                .map(|repo_url| Repository {
-                    ty: "git".to_string(),
-                    url: repo_url,
-                }),
-            files: data.files,
-            browser: data.main,
-            types: data.dts_file,
-        })
+        NpmPackage::base(data, &pkg, &self.manifest)
     }
 
     fn check_optional_fields(&self) {
diff --git a/src/manifest/npm/commonjs.rs b/src/manifest/npm/commonjs.rs
deleted file mode 100644
index ed8b8f99..00000000
--- a/src/manifest/npm/commonjs.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-use manifest::npm::repository::Repository;
-
-#[derive(Serialize)]
-pub struct CommonJSPackage {
-    pub name: String,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub collaborators: Vec<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub description: Option<String>,
-    pub version: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub license: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub repository: Option<Repository>,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub files: Vec<String>,
-    pub main: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub types: Option<String>,
-}
diff --git a/src/manifest/npm/esmodules.rs b/src/manifest/npm/esmodules.rs
deleted file mode 100644
index df73964e..00000000
--- a/src/manifest/npm/esmodules.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-use manifest::npm::repository::Repository;
-
-#[derive(Serialize)]
-pub struct ESModulesPackage {
-    pub name: String,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub collaborators: Vec<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub description: Option<String>,
-    pub version: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub license: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub repository: Option<Repository>,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub files: Vec<String>,
-    pub module: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub types: Option<String>,
-    #[serde(rename = "sideEffects")]
-    pub side_effects: String,
-}
diff --git a/src/manifest/npm/mod.rs b/src/manifest/npm/mod.rs
index c8d65821..82251dfa 100644
--- a/src/manifest/npm/mod.rs
+++ b/src/manifest/npm/mod.rs
@@ -1,16 +1,77 @@
-mod commonjs;
-mod esmodules;
-mod nomodules;
 pub mod repository;
 
-pub use self::commonjs::CommonJSPackage;
-pub use self::esmodules::ESModulesPackage;
-pub use self::nomodules::NoModulesPackage;
+use self::repository::Repository;
+use super::{CargoManifest, NpmData};
 
 #[derive(Serialize)]
-#[serde(untagged)]
-pub enum NpmPackage {
-    CommonJSPackage(CommonJSPackage),
-    ESModulesPackage(ESModulesPackage),
-    NoModulesPackage(NoModulesPackage),
+pub struct NpmPackage {
+    pub name: String,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub collaborators: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub description: Option<String>,
+    pub version: String,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub license: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub repository: Option<Repository>,
+    #[serde(skip_serializing_if = "Vec::is_empty")]
+    pub files: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub browser: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub main: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub module: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub types: Option<String>,
+    #[serde(rename = "sideEffects")]
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub side_effects: Option<String>,
+}
+
+impl NpmPackage {
+    pub(super) fn base(
+        data: NpmData,
+        pkg: &cargo_metadata::Package,
+        manifest: &CargoManifest,
+    ) -> Self {
+        Self {
+            name: data.name,
+            collaborators: pkg.authors.clone(),
+            description: manifest.package.description.clone(),
+            version: pkg.version.clone(),
+            license: manifest.package.license.clone(),
+            repository: manifest
+                .package
+                .repository
+                .clone()
+                .map(|repo_url| Repository {
+                    ty: "git".to_string(),
+                    url: repo_url,
+                }),
+            files: vec![],
+            types: data.dts_file,
+            ..Self::default()
+        }
+    }
+}
+
+impl Default for NpmPackage {
+    fn default() -> Self {
+        Self {
+            name: "".to_owned(),
+            collaborators: vec![],
+            description: None,
+            version: "".to_owned(),
+            license: None,
+            repository: None,
+            files: vec![],
+            browser: None,
+            main: None,
+            module: None,
+            types: None,
+            side_effects: None,
+        }
+    }
 }
diff --git a/src/manifest/npm/nomodules.rs b/src/manifest/npm/nomodules.rs
deleted file mode 100644
index 696a74b0..00000000
--- a/src/manifest/npm/nomodules.rs
+++ /dev/null
@@ -1,20 +0,0 @@
-use manifest::npm::repository::Repository;
-
-#[derive(Serialize)]
-pub struct NoModulesPackage {
-    pub name: String,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub collaborators: Vec<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub description: Option<String>,
-    pub version: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub license: Option<String>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub repository: Option<Repository>,
-    #[serde(skip_serializing_if = "Vec::is_empty")]
-    pub files: Vec<String>,
-    pub browser: String,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub types: Option<String>,
-}