diff --git a/tools/package-tools/gulp/build-tasks-gulp.ts b/tools/package-tools/gulp/build-tasks-gulp.ts
index 140bf50cfaf..8f3c9293f4b 100644
--- a/tools/package-tools/gulp/build-tasks-gulp.ts
+++ b/tools/package-tools/gulp/build-tasks-gulp.ts
@@ -118,7 +118,7 @@ export function createPackageBuildTasks(buildPackage: BuildPackage, preBuildTask
   task(`${taskName}:assets`, assetTasks);
 
   task(`${taskName}:assets:scss`, () => {
-    buildScssPipeline(buildPackage.sourceDir, true)
+    return buildScssPipeline(buildPackage.sourceDir, true)
       .pipe(dest(buildPackage.outputDir))
       .pipe(dest(buildPackage.esm5OutputDir));
     }
@@ -136,7 +136,9 @@ export function createPackageBuildTasks(buildPackage: BuildPackage, preBuildTask
         .pipe(dest(buildPackage.esm5OutputDir));
   });
 
-  task(`${taskName}:assets:inline`, () => inlineResourcesForDirectory(buildPackage.outputDir));
+  task(`${taskName}:assets:inline`, () => {
+    return inlineResourcesForDirectory(buildPackage.outputDir);
+  });
 
   task(`${taskName}:assets:schematics-ts`, () => {
     return tsCompile('tsc', ['-p', join(schematicsDir, 'tsconfig.json')]);