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 65ea0742abdc..28b536265744 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..ce3bee6bde6f 100644
--- a/packages/angular_devkit/build_angular/src/extract-i18n/index.ts
+++ b/packages/angular_devkit/build_angular/src/extract-i18n/index.ts
@@ -74,7 +74,7 @@ export class ExtractI18nBuilder implements Builder<ExtractI18nBuilderOptions> {
         architect.validateBuilderOptions(browserBuilderConfig, browserDescription)),
       map(browserBuilderConfig => browserBuilderConfig.options),
       concatMap((validatedBrowserOptions) => {
-        const browserOptions = validatedBrowserOptions;
+        const browserOptions = validatedBrowserOptions as NormalizedBrowserBuilderSchema;
 
         // We need to determine the outFile name so that AngularCompiler can retrieve it.
         let outFile = options.outFile || getI18nOutfile(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 c90e58644ec3..ea579e4253ea 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 +5,8 @@
  * 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.
@@ -76,7 +78,7 @@ export interface BuildWebpackServerSchema {
   /**
    * Replace files with other files in the build.
    */
-  fileReplacements: FileReplacements[];
+  fileReplacements: FileReplacement[];
   /**
    * Define the output filename cache-busting hashing mode.
    */