diff --git a/packages/gasket-plugin-nextjs/lib/webpack-config.js b/packages/gasket-plugin-nextjs/lib/webpack-config.js
index af56fa7a1..13d9f859c 100644
--- a/packages/gasket-plugin-nextjs/lib/webpack-config.js
+++ b/packages/gasket-plugin-nextjs/lib/webpack-config.js
@@ -53,6 +53,8 @@ function webpackConfigHook(gasket, webpackConfig, { webpack, isServer }) {
     if (!isServer) {
       exclude('./gasket.js');
       exclude('./src/gasket.js');
+      exclude('./gasket.mjs');
+      exclude('./src/gasket.mjs');
       exclude('./gasket.ts');
       exclude('./src/gasket.ts');
       exclude('./dist/gasket.js');
diff --git a/packages/gasket-plugin-nextjs/test/webpack-config.test.js b/packages/gasket-plugin-nextjs/test/webpack-config.test.js
index 4aa3f350a..1ab3e59ba 100644
--- a/packages/gasket-plugin-nextjs/test/webpack-config.test.js
+++ b/packages/gasket-plugin-nextjs/test/webpack-config.test.js
@@ -10,6 +10,8 @@ describe('webpackConfigHook', () => {
   let mockGasket, mockWebpackConfig, mockContext;
 
   beforeEach(() => {
+    tryResolve.mockImplementation((moduleName) => moduleName);
+
     mockGasket = {
       config: {
         root: '/path/to/app'
@@ -46,12 +48,26 @@ describe('webpackConfigHook', () => {
     expect(result.resolve.alias).toEqual(expect.objectContaining({ [target]: false }));
   });
 
-  it('adds empty alias for gasket file in client', () => {
+  it('adds empty alias for gasket.js file in client', () => {
     tryResolve.mockReturnValue(mockFilename);
     const result = webpackConfig(mockGasket, mockWebpackConfig, mockContext);
     expect(result.resolve.alias).toEqual(expect.objectContaining({ [mockFilename]: false }));
   });
 
+  it('adds empty alias for expected default filenames', () => {
+    const mjsFilename = '/path/to/app/gasket.mjs';
+    tryResolve.mockReturnValue(mjsFilename);
+    const result = webpackConfig(mockGasket, mockWebpackConfig, mockContext);
+    expect(result.resolve.alias).toEqual(expect.objectContaining({ [mjsFilename]: false }));
+  });
+
+  it('adds empty alias for gasket.ts file in client', () => {
+    const tsFilename = '/path/to/app/gasket.ts';
+    tryResolve.mockReturnValue(tsFilename);
+    const result = webpackConfig(mockGasket, mockWebpackConfig, mockContext);
+    expect(result.resolve.alias).toEqual(expect.objectContaining({ [tsFilename]: false }));
+  });
+
   it('adds validateNoGasketCore to externals for client', () => {
     const result = webpackConfig(mockGasket, mockWebpackConfig, mockContext);
     expect(result.externals[0]).toBe(validateNoGasketCore);