diff --git a/tools/package-tools/build-release.ts b/tools/package-tools/build-release.ts
index 09c9d718cd3..93a1dde89cf 100644
--- a/tools/package-tools/build-release.ts
+++ b/tools/package-tools/build-release.ts
@@ -1,7 +1,6 @@
 import {join} from 'path';
 import {mkdirpSync} from 'fs-extra';
 import {copyFiles} from './copy-files';
-import {addPureAnnotationsToFile} from './pure-annotations';
 import {replaceVersionPlaceholders} from './version-placeholders';
 import {inlinePackageMetadataFiles} from './metadata-inlining';
 import {createTypingsReexportFile} from './typings-reexport';
@@ -43,8 +42,6 @@ export function composeRelease(packageName: string, options: ComposeReleaseOptio
   if (options.useSecondaryEntryPoints) {
     createFilesForSecondaryEntryPoint(packageName, packagePath, releasePath);
   }
-
-  addPureAnnotationsToFile(join(releasePath, '@angular', `${packageName}.es5.js`));
 }
 
 /** Creates files necessary for a secondary entry-point. */
diff --git a/tools/package-tools/copy-files.ts b/tools/package-tools/copy-files.ts
index 48412d3ef9b..c9baf5fe02b 100644
--- a/tools/package-tools/copy-files.ts
+++ b/tools/package-tools/copy-files.ts
@@ -5,7 +5,7 @@ import {join, dirname} from 'path';
 /** Function to copy files that match a glob to another directory. */
 export function copyFiles(fromPath: string, fileGlob: string, outDir: string) {
   glob(fileGlob, {cwd: fromPath}).forEach(filePath => {
-    let fileDestPath = join(outDir, filePath);
+    const fileDestPath = join(outDir, filePath);
     mkdirpSync(dirname(fileDestPath));
     copySync(join(fromPath, filePath), fileDestPath);
   });
diff --git a/tools/package-tools/entry-point-package-json.ts b/tools/package-tools/entry-point-package-json.ts
index 60026c172f1..f804be61719 100644
--- a/tools/package-tools/entry-point-package-json.ts
+++ b/tools/package-tools/entry-point-package-json.ts
@@ -12,5 +12,5 @@ export function createEntryPointPackageJson(destDir: string, packageName: string
     es2015: `../@angular/${packageName}/${entryPointName}.js`,
   };
 
-  writeFileSync(join(destDir, 'package.json'), JSON.stringify(content), 'utf-8');
+  writeFileSync(join(destDir, 'package.json'), JSON.stringify(content, null, 2), 'utf-8');
 }
diff --git a/tools/package-tools/metadata-reexport.ts b/tools/package-tools/metadata-reexport.ts
index 60836016bbd..cd79e86c6ca 100644
--- a/tools/package-tools/metadata-reexport.ts
+++ b/tools/package-tools/metadata-reexport.ts
@@ -3,11 +3,13 @@ import {join} from 'path';
 
 /** Creates a metadata file that re-exports the metadata bundle inside of the typings. */
 export function createMetadataReexportFile(destDir: string, from: string, name: string) {
-  const metadataReExport = `{
-    "__symbolic":"module",
-    "version":3,"metadata":{},
-    "exports":[{"from":"${from}"}],
-    "flatModuleIndexRedirect": true
-  }`;
-  writeFileSync(join(destDir, `${name}.metadata.json`), metadataReExport, 'utf-8');
+  const metadataJsonContent = JSON.stringify({
+    __symbolic: 'module',
+    version: 3,
+    metadata: {},
+    exports: [{from}],
+    flatModuleIndexRedirect: true
+  }, null, 2);
+
+  writeFileSync(join(destDir, `${name}.metadata.json`), metadataJsonContent, 'utf-8');
 }
diff --git a/tools/package-tools/pure-annotations.ts b/tools/package-tools/pure-annotations.ts
deleted file mode 100644
index 9fa971e4c01..00000000000
--- a/tools/package-tools/pure-annotations.ts
+++ /dev/null
@@ -1,33 +0,0 @@
-import {readFileSync, writeFileSync} from 'fs';
-
-/** Regex that matches downleveled class IIFE expressions. Used to add the pure annotations. */
-const classIfeeRegex =
-  new RegExp('^(var (\\S+) = )(\\(function \\(\\) \\{[\\n\\r]*(?:    (?:\\/\\*\\*| \\*|\\*\\/|' +
-    '\\/\\/)[^\\n\\r]*[\\n\\r]*)*    function \\2\\([^\\)]*\\) \\{[\\n\\r]*)', 'mg');
-
-/** Regex that matches downleveled class IIFE expressions with _extends statements */
-const classExtendsIfeeRegex =
-  /^(var (\S+) = )(\(function \(_super\) {[\n\r]*    tslib.*\.__extends\(\2, _super\);[\n\r]*)/gm;
-
-/**
- * Adds `@__PURE__` annotation comments to IIFEs containing ES5-downleveled classes generated by
- * TypeScript so that Uglify can tree-shake classes that are not referenced.
- *
- * @param fileContent The content of the file for which `@__PURE__` will be added.
- * @returns The content of the file with `@__PURE__` annotations added.
- */
-export function addPureAnnotations(fileContent: string) {
-  return fileContent
-  // Prefix downleveled classes w/ the @__PURE__ annotation.
-    .replace(classIfeeRegex, '$1/*@__PURE__*/$3')
-    // Prefix downleveled classes that extend another class w/ the @__PURE__ annotation
-    .replace(classExtendsIfeeRegex, '$1/*@__PURE__*/$3');
-}
-
-/** Adds Uglify "@__PURE__" decorations to the specified file. */
-export function addPureAnnotationsToFile(inputFile: string) {
-  const originalContent = readFileSync(inputFile, 'utf-8');
-  const annotatedContent = addPureAnnotations(originalContent);
-
-  writeFileSync(inputFile, annotatedContent, 'utf-8');
-}