diff --git a/packages/@angular/cli/models/config/config.ts b/packages/@angular/cli/models/config/config.ts
index 37290ed3808d..594e5aab1225 100644
--- a/packages/@angular/cli/models/config/config.ts
+++ b/packages/@angular/cli/models/config/config.ts
@@ -1,5 +1,6 @@
 import * as fs from 'fs';
 import * as path from 'path';
+import * as ts from 'typescript';
 
 import {SchemaClass, SchemaClassFactory} from '@ngtools/json-schema';
 
@@ -70,11 +71,11 @@ export class CliConfig<JsonType> {
 
   static fromConfigPath<T>(configPath: string, otherPath: string[] = []): CliConfig<T> {
     const configContent = fs.existsSync(configPath)
-      ? fs.readFileSync(configPath, 'utf-8')
+      ? ts.sys.readFile(configPath)
       : '{}';
     const schemaContent = fs.readFileSync(DEFAULT_CONFIG_SCHEMA_PATH, 'utf-8');
     const otherContents = otherPath
-      .map(path => fs.existsSync(path) && fs.readFileSync(path, 'utf-8'))
+      .map(path => fs.existsSync(path) && ts.sys.readFile(path))
       .filter(content => !!content);
 
     let content: T;
diff --git a/packages/@ngtools/webpack/src/plugin.ts b/packages/@ngtools/webpack/src/plugin.ts
index acf7e2b2f629..e744a0a04532 100644
--- a/packages/@ngtools/webpack/src/plugin.ts
+++ b/packages/@ngtools/webpack/src/plugin.ts
@@ -103,7 +103,7 @@ export class AotPlugin implements Tapable {
 
     let tsConfigJson: any = null;
     try {
-      tsConfigJson = JSON.parse(fs.readFileSync(this._tsConfigPath, 'utf8'));
+      tsConfigJson = JSON.parse(ts.sys.readFile(this._tsConfigPath));
     } catch (err) {
       throw new Error(`An error happened while parsing ${this._tsConfigPath} JSON: ${err}.`);
     }
diff --git a/tests/e2e/tests/misc/different-file-format.ts b/tests/e2e/tests/misc/different-file-format.ts
new file mode 100644
index 000000000000..d3bb097f9955
--- /dev/null
+++ b/tests/e2e/tests/misc/different-file-format.ts
@@ -0,0 +1,15 @@
+import {ng} from '../../utils/process';
+import * as fs from '../../utils/fs';
+
+
+const options = {
+  encoding: 'utf8'
+};
+
+
+export default function() {
+  return Promise.resolve()
+    .then(() => fs.prependToFile('./src/tsconfig.json', '\ufeff', options))
+    .then(() => fs.prependToFile('./angular-cli.json', '\ufeff', options))
+    .then(() => ng('build', '--env=dev'));
+}
diff --git a/tests/e2e/utils/fs.ts b/tests/e2e/utils/fs.ts
index b1f8606c0184..fa53ad0725a7 100644
--- a/tests/e2e/utils/fs.ts
+++ b/tests/e2e/utils/fs.ts
@@ -15,9 +15,9 @@ export function readFile(fileName: string) {
   });
 }
 
-export function writeFile(fileName: string, content: string) {
+export function writeFile(fileName: string, content: string, options?: any) {
   return new Promise<void>((resolve, reject) => {
-    fs.writeFile(fileName, content, (err: any) => {
+    fs.writeFile(fileName, content, options, (err: any) => {
       if (err) {
         reject(err);
       } else {
@@ -97,15 +97,15 @@ export function replaceInFile(filePath: string, match: RegExp, replacement: stri
 }
 
 
-export function appendToFile(filePath: string, text: string) {
+export function appendToFile(filePath: string, text: string, options?: any) {
   return readFile(filePath)
-    .then((content: string) => writeFile(filePath, content.concat(text)));
+    .then((content: string) => writeFile(filePath, content.concat(text), options));
 }
 
 
-export function prependToFile(filePath: string, text: string) {
+export function prependToFile(filePath: string, text: string, options?: any) {
   return readFile(filePath)
-    .then((content: string) => writeFile(filePath, text.concat(content)));
+    .then((content: string) => writeFile(filePath, text.concat(content), options));
 }