diff --git a/lib/mock-helper/mock-helper.default-replace.ts b/lib/mock-helper/mock-helper.default-replace.ts
new file mode 100644
index 0000000000..6222d5e120
--- /dev/null
+++ b/lib/mock-helper/mock-helper.default-replace.ts
@@ -0,0 +1,6 @@
+import { AnyType } from '../common/core.types';
+import ngMocksUniverse from '../common/ng-mocks-universe';
+
+export default (source: AnyType<any>, destination: AnyType<any>): void => {
+  ngMocksUniverse.getDefaults().set(source, destination);
+};
diff --git a/lib/mock-helper/mock-helper.ts b/lib/mock-helper/mock-helper.ts
index 732d5d9420..cc55bca1de 100644
--- a/lib/mock-helper/mock-helper.ts
+++ b/lib/mock-helper/mock-helper.ts
@@ -12,6 +12,7 @@ import mockHelperAutoSpy from './mock-helper.auto-spy';
 import mockHelperDefaultExclude from './mock-helper.default-exclude';
 import mockHelperDefaultKeep from './mock-helper.default-keep';
 import mockHelperDefaultMock from './mock-helper.default-mock';
+import mockHelperDefaultReplace from './mock-helper.default-replace';
 import mockHelperFaster from './mock-helper.faster';
 import mockHelperFind from './mock-helper.find';
 import mockHelperFindAll from './mock-helper.find-all';
@@ -70,6 +71,11 @@ export const ngMocks: {
    */
   defaultMock<T>(def: AnyType<T>, handler?: (value: T, injector: Injector) => void | Partial<T>): void;
 
+  /**
+   * @see https://github.com/ike18t/ng-mocks#ngmocksdefaultreplace
+   */
+  defaultReplace(source: AnyType<any>, destination: AnyType<any>): void;
+
   /**
    * @see https://github.com/ike18t/ng-mocks#making-angular-tests-faster
    */
@@ -259,6 +265,7 @@ export const ngMocks: {
   defaultExclude: mockHelperDefaultExclude,
   defaultKeep: mockHelperDefaultKeep,
   defaultMock: mockHelperDefaultMock,
+  defaultReplace: mockHelperDefaultReplace,
   faster: mockHelperFaster,
   find: mockHelperFind,
   findAll: mockHelperFindAll,
diff --git a/tests/ng-mocks-default-replace-modules/fixtures.ts b/tests/ng-mocks-default-replace-modules/fixtures.ts
new file mode 100644
index 0000000000..03e46f52ab
--- /dev/null
+++ b/tests/ng-mocks-default-replace-modules/fixtures.ts
@@ -0,0 +1,35 @@
+import { Component, NgModule } from '@angular/core';
+
+@Component({
+  selector: 'target',
+  template: '{{ name }}',
+})
+export class Target1Component {
+  public readonly name = 'target1';
+}
+
+@NgModule({
+  declarations: [Target1Component],
+  exports: [Target1Component],
+})
+export class Target1Module {}
+
+@Component({
+  selector: 'target',
+  template: '{{ name }}',
+})
+export class Target2Component {
+  public readonly name = 'target2';
+}
+
+@NgModule({
+  declarations: [Target2Component],
+  exports: [Target2Component],
+})
+export class Target2Module {}
+
+@NgModule({
+  exports: [Target1Module],
+  imports: [Target1Module],
+})
+export class Target3Module {}
diff --git a/tests/ng-mocks-default-replace-modules/test.spec.ts b/tests/ng-mocks-default-replace-modules/test.spec.ts
new file mode 100644
index 0000000000..0f22cd76f4
--- /dev/null
+++ b/tests/ng-mocks-default-replace-modules/test.spec.ts
@@ -0,0 +1,25 @@
+import { TestBed } from '@angular/core/testing';
+import { MockModule, MockRender, ngMocks } from 'ng-mocks';
+
+import {
+  Target1Module,
+  Target2Module,
+  Target3Module,
+} from './fixtures';
+
+ngMocks.defaultReplace(Target1Module, Target2Module);
+
+describe('ng-mocks-default-replace-modules', () => {
+  beforeEach(() => {
+    return TestBed.configureTestingModule({
+      imports: [MockModule(Target3Module)],
+    });
+  });
+
+  it('replaces Target1Module with Target2Module', () => {
+    const fixture = MockRender('<target></target>');
+    expect(fixture.nativeElement.innerHTML).toEqual(
+      '<target>target2</target>',
+    );
+  });
+});
diff --git a/tests/ng-mocks-default-replace/test.spec.ts b/tests/ng-mocks-default-replace/test.spec.ts
new file mode 100644
index 0000000000..ad9c09977b
--- /dev/null
+++ b/tests/ng-mocks-default-replace/test.spec.ts
@@ -0,0 +1,112 @@
+import { Component, NgModule } from '@angular/core';
+import { TestBed } from '@angular/core/testing';
+import {
+  MockBuilder,
+  MockComponent,
+  MockModule,
+  MockRender,
+  ngMocks,
+} from 'ng-mocks';
+
+@Component({
+  selector: 'target',
+  template: '{{ name }}',
+})
+class TargetComponent {
+  public readonly name = 'target';
+}
+
+@Component({
+  selector: 'target',
+  template: '{{ name }}',
+})
+class FakeComponent {
+  public readonly name = 'fake';
+}
+
+@NgModule({
+  declarations: [TargetComponent],
+  exports: [TargetComponent],
+})
+class TargetModule {}
+
+ngMocks.defaultReplace(TargetComponent, FakeComponent);
+
+describe('ng-mocks-default-replace', () => {
+  describe('MockComponent', () => {
+    beforeEach(() =>
+      TestBed.configureTestingModule({
+        declarations: [MockComponent(TargetComponent)],
+      }),
+    );
+
+    it('works as usual', () => {
+      const fixture = MockRender('<target></target>');
+      expect(fixture.nativeElement.innerHTML).toEqual(
+        '<target></target>',
+      );
+    });
+  });
+
+  describe('MockModule', () => {
+    beforeEach(() =>
+      TestBed.configureTestingModule({
+        imports: [MockModule(TargetModule)],
+      }),
+    );
+
+    it('replaces out of the box', () => {
+      const fixture = MockRender('<target></target>');
+      expect(fixture.nativeElement.innerHTML).toEqual(
+        '<target>fake</target>',
+      );
+    });
+  });
+
+  describe('MockBuilder:default', () => {
+    beforeEach(() => MockBuilder(null, TargetModule));
+
+    it('replaces out of the box', () => {
+      const fixture = MockRender('<target></target>');
+      expect(fixture.nativeElement.innerHTML).toEqual(
+        '<target>fake</target>',
+      );
+    });
+  });
+
+  describe('MockBuilder:exclude', () => {
+    beforeEach(() =>
+      MockBuilder(null, TargetModule).exclude(TargetComponent),
+    );
+
+    it('switches to exclude', () => {
+      expect(() => MockRender('<target></target>')).toThrow();
+    });
+  });
+
+  describe('MockBuilder:mock', () => {
+    beforeEach(() =>
+      MockBuilder(null, TargetModule).mock(TargetComponent),
+    );
+
+    it('switches to mock', () => {
+      const fixture = MockRender('<target></target>');
+      expect(fixture.nativeElement.innerHTML).toEqual(
+        '<target></target>',
+      );
+    });
+  });
+
+  describe('MockBuilder:keep', () => {
+    beforeEach(() =>
+      MockBuilder(null, TargetModule).keep(TargetComponent),
+    );
+
+    it('switches to keep', () => {
+      const fixture = MockRender('<target></target>');
+      expect(fixture.nativeElement.innerHTML).toEqual(
+        '<target>target</target>',
+      );
+    });
+  });
+});