diff --git a/packages/browser/.npmignore b/packages/browser/.npmignore
index 5c6d6b607beb..643a96e2e5f4 100644
--- a/packages/browser/.npmignore
+++ b/packages/browser/.npmignore
@@ -1,6 +1,6 @@
-# Info: the paths in this file are adjusted to match once this
-# file is copied to `./build`. This is done by a postbuild script
-# located in sentry-javascript/scripts/postbuild.sh
+# Info: the paths in this file are specified so that they align with the file
+# structure in `./build` where this file is copied to. This is done by the
+# postbuild script `sentry-javascript/scripts/postbuild.ts`.
 
 *
 
diff --git a/packages/browser/package.json b/packages/browser/package.json
index da5acad0ed2c..d9d2b7691625 100644
--- a/packages/browser/package.json
+++ b/packages/browser/package.json
@@ -44,7 +44,7 @@
     "webpack": "^4.30.0"
   },
   "scripts": {
-    "build": "run-p build:cjs build:esm build:bundle build:types && bash ../../scripts/postbuild.sh",
+    "build": "run-p build:cjs build:esm build:bundle build:types && ts-node ../../scripts/postbuild.ts",
     "build:bundle": "rollup --config",
     "build:cjs": "tsc -p tsconfig.cjs.json",
     "build:dev": "run-p build:cjs build:esm build:types",
diff --git a/scripts/postbuild.sh b/scripts/postbuild.sh
deleted file mode 100644
index 423f36c076d8..000000000000
--- a/scripts/postbuild.sh
+++ /dev/null
@@ -1,40 +0,0 @@
-#!/bin/sh
-
-# This script prepares the `build` directory for NPM package creation.
-# It first copies all non-code files into the `build` directory, including `package.json` which
-# is edited via a few `sed` commands. These edits include corrections of paths (e.g. entry points)
-# in the copied package.json so that they align with the directory structure inside `build`.
-
-BUILD_DIR=build
-
-ASSETS="README.md
-LICENSE
-package.json
-.npmignore"
-
-# check if build dir exists
-if [ ! -d $BUILD_DIR ]; then
-  echo "Directory ${BUILD_DIR}/ DOES NOT exist."
-  echo "This script should only be executed after you've run \`yarn build\`."
-  exit 1
-fi
-
-# copy non-code assets to build dir
-for f in $ASSETS; do
-  cp $f $BUILD_DIR/
-done
-
-# package.json modifications
-
-# sed command to modify package.json entry points in build dir
-# remove `BUILD_DIR` from `main`, `module` and `type` entry point paths
-entryPointsCommand="/\"(main|module|types)\": .*,/s/$BUILD_DIR\///"
-
-# use empty backup file extension for sed in-place editing on MacOS and no backup for other platforms
-if [[ $(uname) == "Darwin" ]]; then
-  sed -i "" -E "$entryPointsCommand" $BUILD_DIR/package.json
-else
-  sed -i -E "$entryPointsCommand#" $BUILD_DIR/package.json
-fi
-
-echo "Successfully finished postbuild commands"
diff --git a/scripts/postbuild.ts b/scripts/postbuild.ts
new file mode 100644
index 000000000000..959569bec034
--- /dev/null
+++ b/scripts/postbuild.ts
@@ -0,0 +1,63 @@
+/*
+  This script prepares the central `build` directory for NPM package creation.
+  It first copies all non-code files into the `build` directory, including `package.json`, which
+  is edited to adjust entry point paths. These corrections are performed so that the paths align with
+  the directory structure inside `build`.
+*/
+
+import * as fs from 'fs';
+
+import * as path from 'path';
+
+const BUILD_DIR = 'build';
+const ASSETS = ['README.md', 'LICENSE', 'package.json', '.npmignore'];
+const ENTRY_POINTS = ['main', 'module', 'types'];
+
+// check if build dir exists
+try {
+  if (!fs.existsSync(path.resolve(BUILD_DIR))) {
+    console.error(`Directory ${BUILD_DIR} DOES NOT exist`);
+    console.error("This script should only be executed after you've run `yarn build`.");
+    process.exit(1);
+  }
+} catch (error) {
+  console.error(`Error while looking up directory ${BUILD_DIR}`);
+  process.exit(1);
+}
+
+// copy non-code assets to build dir
+ASSETS.forEach(asset => {
+  const assetPath = path.resolve(asset);
+  try {
+    if (!fs.existsSync(assetPath)) {
+      console.error(`Asset ${asset} does not exist.`);
+      process.exit(1);
+    }
+    fs.copyFileSync(assetPath, path.resolve(BUILD_DIR, asset));
+  } catch (error) {
+    console.error(`Error while copying ${asset} to ${BUILD_DIR}`);
+    process.exit(1);
+  }
+});
+
+// package.json modifications
+const packageJsonPath = path.resolve(BUILD_DIR, 'package.json');
+const pkgJson: { [key: string]: unknown } = require(packageJsonPath);
+
+// modify entry points to point to correct paths (i.e. strip out the build directory)
+ENTRY_POINTS.filter(entryPoint => pkgJson[entryPoint]).forEach(entryPoint => {
+  pkgJson[entryPoint] = (pkgJson[entryPoint] as string).replace(`${BUILD_DIR}/`, '');
+});
+
+delete pkgJson.scripts;
+delete pkgJson.volta;
+
+// write modified package.json to file (pretty-printed with 2 spaces)
+try {
+  fs.writeFileSync(packageJsonPath, JSON.stringify(pkgJson, null, 2));
+} catch (error) {
+  console.error(`Error while writing package.json to disk`);
+  process.exit(1);
+}
+
+console.log(`\nSuccessfully finished postbuild commands for ${pkgJson.name}`);