diff --git a/packages/ckeditor5-package-generator/lib/templates/js-legacy/.eslintrc.cjs b/packages/ckeditor5-package-generator/lib/templates/js-legacy/.eslintrc.cjs
index 1caff49..c52170a 100644
--- a/packages/ckeditor5-package-generator/lib/templates/js-legacy/.eslintrc.cjs
+++ b/packages/ckeditor5-package-generator/lib/templates/js-legacy/.eslintrc.cjs
@@ -16,7 +16,8 @@ module.exports = {
 		// Also, importing non-DLL packages is not allowed. If the package requires other features to work, they should be
 		// specified as soft-requirements.
 		// Read more: https://ckeditor.com/docs/ckeditor5/latest/builds/guides/migration/migration-to-26.html#soft-requirements.
-		'ckeditor5-rules/ckeditor-imports': 'error'
+		'ckeditor5-rules/ckeditor-imports': 'error',
+		'ckeditor5-rules/allow-imports-only-from-main-package-entry-point': 'error'
 	},
 	overrides: [
 		{
diff --git a/packages/ckeditor5-package-generator/lib/templates/js/.eslintrc.cjs b/packages/ckeditor5-package-generator/lib/templates/js/.eslintrc.cjs
index 630603e..881ea16 100644
--- a/packages/ckeditor5-package-generator/lib/templates/js/.eslintrc.cjs
+++ b/packages/ckeditor5-package-generator/lib/templates/js/.eslintrc.cjs
@@ -9,6 +9,9 @@ module.exports = {
 		// Ignore the entire `dist/`.
 		'dist/**'
 	],
+	rules: {
+		'ckeditor5-rules/allow-imports-only-from-main-package-entry-point': 'error'
+	},
 	overrides: [
 		{
 			files: [ 'tests/**/*.js', 'sample/**/*.js' ],