diff --git a/packages/angular_devkit/build_angular/test/browser/web-worker_spec_large.ts b/packages/angular_devkit/build_angular/test/browser/web-worker_spec_large.ts
index 208618272b82..2f161af1624d 100644
--- a/packages/angular_devkit/build_angular/test/browser/web-worker_spec_large.ts
+++ b/packages/angular_devkit/build_angular/test/browser/web-worker_spec_large.ts
@@ -9,7 +9,8 @@
 import { Architect } from '@angular-devkit/architect';
 import { TestLogger } from '@angular-devkit/architect/testing';
 import { join, virtualFs } from '@angular-devkit/core';
-import { debounceTime, takeWhile, tap } from 'rxjs/operators';
+import { timer } from 'rxjs';
+import { debounceTime, map, switchMap, takeWhile, tap } from 'rxjs/operators';
 import { browserBuild, createArchitect, host, outputPath } from '../utils';
 
 
@@ -140,15 +141,14 @@ describe('Browser Builder Web Worker support', () => {
     const workerPath = join(outputPath, '0.worker.js');
     let workerContent = '';
 
-    const run = await architect.scheduleTarget(target, overrides);
-    await run.output.pipe(
-      // Wait for files to be written to disk.
-      // FIXME: Not quite sure why such a long 'debounceTime' is needed.
-      // Anything under `2500` is a constant failure locally when using
-      // 'fdescribe' and this tests doesn't run as first one and is also rather flaky on CI.
-      // It seems that the outputted files contents don't get updated in time.
-      debounceTime(2500),
-      tap((buildEvent) => expect(buildEvent.success).toBe(true, 'build should succeed')),
+    // The current linux-based CI environments may not fully settled in regards to filesystem
+    // changes from previous tests which reuse the same directory and fileset.
+    // The initial delay helps mitigate false positive rebuild triggers in such scenarios.
+    const { run } = await timer(1000).pipe(
+      switchMap(() => architect.scheduleTarget(target, overrides)),
+      switchMap(run => run.output.pipe(map(output => ({ run, output })))),
+      debounceTime(500),
+      tap(({ output }) => expect(output.success).toBe(true, 'build should succeed')),
       tap(() => {
         switch (phase) {
           case 1:
diff --git a/packages/schematics/angular/workspace/files/tsconfig.json.template b/packages/schematics/angular/workspace/files/tsconfig.json.template
index 896ab790a464..f89b38bbce6c 100644
--- a/packages/schematics/angular/workspace/files/tsconfig.json.template
+++ b/packages/schematics/angular/workspace/files/tsconfig.json.template
@@ -8,6 +8,7 @@
     "noImplicitThis": true,
     "noFallthroughCasesInSwitch": true,
     "strictNullChecks": true,<% } %>
+    "skipLibCheck": true,
     "sourceMap": true,
     "declaration": false,
     "downlevelIteration": true,
diff --git a/scripts/test.ts b/scripts/test.ts
index de17c790e2cb..eb80a32801fe 100644
--- a/scripts/test.ts
+++ b/scripts/test.ts
@@ -23,6 +23,7 @@ const knownFlakes = [
   // Rebuild tests in test-large are flakey if not run as the first suite.
   // https://github.com/angular/angular-cli/pull/15204
   'packages/angular_devkit/build_angular/test/browser/rebuild_spec_large.ts',
+  'packages/angular_devkit/build_angular/test/browser/web-worker_spec_large.ts',
 ];
 
 const projectBaseDir = join(__dirname, '..');
diff --git a/tests/angular_devkit/build_angular/hello-world-app-ve/tsconfig.json b/tests/angular_devkit/build_angular/hello-world-app-ve/tsconfig.json
index 641ccb244858..019f3395ce0c 100644
--- a/tests/angular_devkit/build_angular/hello-world-app-ve/tsconfig.json
+++ b/tests/angular_devkit/build_angular/hello-world-app-ve/tsconfig.json
@@ -5,6 +5,7 @@
     "outDir": "./dist/out-tsc",
     "sourceMap": true,
     "declaration": false,
+    "skipLibCheck": true,
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
diff --git a/tests/angular_devkit/build_angular/hello-world-app/tsconfig.json b/tests/angular_devkit/build_angular/hello-world-app/tsconfig.json
index 0b2d4a18fce3..440dd0d48ef8 100644
--- a/tests/angular_devkit/build_angular/hello-world-app/tsconfig.json
+++ b/tests/angular_devkit/build_angular/hello-world-app/tsconfig.json
@@ -5,6 +5,7 @@
     "outDir": "./dist/out-tsc",
     "sourceMap": true,
     "declaration": false,
+    "skipLibCheck": true,
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
diff --git a/tests/angular_devkit/build_ng_packagr/ng-packaged-ve/tsconfig.json b/tests/angular_devkit/build_ng_packagr/ng-packaged-ve/tsconfig.json
index cc264e55b22d..44a248786405 100644
--- a/tests/angular_devkit/build_ng_packagr/ng-packaged-ve/tsconfig.json
+++ b/tests/angular_devkit/build_ng_packagr/ng-packaged-ve/tsconfig.json
@@ -5,6 +5,7 @@
     "outDir": "./dist/out-tsc",
     "sourceMap": true,
     "declaration": false,
+    "skipLibCheck": true,
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
diff --git a/tests/angular_devkit/build_ng_packagr/ng-packaged/tsconfig.json b/tests/angular_devkit/build_ng_packagr/ng-packaged/tsconfig.json
index 40def946d5f4..a7adf91b1716 100644
--- a/tests/angular_devkit/build_ng_packagr/ng-packaged/tsconfig.json
+++ b/tests/angular_devkit/build_ng_packagr/ng-packaged/tsconfig.json
@@ -5,6 +5,7 @@
     "outDir": "./dist/out-tsc",
     "sourceMap": true,
     "declaration": false,
+    "skipLibCheck": true,
     "moduleResolution": "node",
     "emitDecoratorMetadata": true,
     "experimentalDecorators": true,
diff --git a/tests/legacy-cli/e2e/tests/build/skip-lib-check.ts b/tests/legacy-cli/e2e/tests/build/skip-lib-check.ts
new file mode 100644
index 000000000000..79c2a753e170
--- /dev/null
+++ b/tests/legacy-cli/e2e/tests/build/skip-lib-check.ts
@@ -0,0 +1,11 @@
+import { ng } from '../../utils/process';
+import { createProject, updateTsConfig } from '../../utils/project';
+
+
+export default async function() {
+  await createProject('strict-workspace-test-project', '--strict');
+  await updateTsConfig(json => {
+    json['compilerOptions']['skipLibCheck'] = false;
+  });
+  await ng('build');
+}