diff --git a/packages/angular_devkit/build_angular/src/browser/schema.d.ts b/packages/angular_devkit/build_angular/src/browser/schema.d.ts
index 0cd707918eb2..fc4f700010e7 100644
--- a/packages/angular_devkit/build_angular/src/browser/schema.d.ts
+++ b/packages/angular_devkit/build_angular/src/browser/schema.d.ts
@@ -49,7 +49,7 @@ export interface BrowserBuilderSchema {
   /**
    * Replace files with other files in the build.
    */
-  fileReplacements: FileReplacements[];
+  fileReplacements: FileReplacement[];
 
   /**
    * Path where output will be placed.
diff --git a/packages/angular_devkit/build_angular/src/extract-i18n/index.ts b/packages/angular_devkit/build_angular/src/extract-i18n/index.ts
index ead3923d38f8..72752838f18f 100644
--- a/packages/angular_devkit/build_angular/src/extract-i18n/index.ts
+++ b/packages/angular_devkit/build_angular/src/extract-i18n/index.ts
@@ -85,7 +85,8 @@ export class ExtractI18nBuilder implements Builder<ExtractI18nBuilderOptions> {
 
         // Extracting i18n uses the browser target webpack config with some specific options.
         const webpackConfig = this.buildWebpackConfig(root, projectRoot, {
-          ...browserOptions,
+          // todo: remove this casting when 'CurrentFileReplacement' is changed to 'FileReplacement'
+          ...(browserOptions as NormalizedBrowserBuilderSchema),
           optimization: false,
           i18nLocale: options.i18nLocale,
           i18nFormat: options.i18nFormat,
diff --git a/packages/angular_devkit/build_angular/src/server/schema.d.ts b/packages/angular_devkit/build_angular/src/server/schema.d.ts
index 16beda1fd8fb..24b575422afd 100644
--- a/packages/angular_devkit/build_angular/src/server/schema.d.ts
+++ b/packages/angular_devkit/build_angular/src/server/schema.d.ts
@@ -5,6 +5,9 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
+
+import { FileReplacement } from '../browser/schema';
+
 export interface BuildWebpackServerSchema {
   /**
    * The name of the TypeScript configuration file.
@@ -80,7 +83,7 @@ export interface BuildWebpackServerSchema {
   /**
    * Replace files with other files in the build.
    */
-  fileReplacements: FileReplacements[];
+  fileReplacements: FileReplacement[];
   /**
    * Define the output filename cache-busting hashing mode.
    */
@@ -125,9 +128,9 @@ export interface BuildWebpackServerSchema {
    * Run build when files change.
    */
   watch?: boolean;
-    /**
-   * Enable and define the file watching poll time period in milliseconds.
-   */
+  /**
+ * Enable and define the file watching poll time period in milliseconds.
+ */
   poll?: number;
 }