diff --git a/lib/init/autoconfig.js b/lib/init/autoconfig.js
index 054c538496f..3233f686539 100644
--- a/lib/init/autoconfig.js
+++ b/lib/init/autoconfig.js
@@ -11,7 +11,11 @@
 
 const equal = require("fast-deep-equal"),
     recConfig = require("../../conf/eslint-recommended"),
-    ConfigOps = require("@eslint/eslintrc/lib/shared/config-ops"),
+    {
+        Legacy: {
+            ConfigOps
+        }
+    } = require("@eslint/eslintrc"),
     { Linter } = require("../linter"),
     configRule = require("./config-rule");
 
diff --git a/lib/init/config-initializer.js b/lib/init/config-initializer.js
index 3c7f2ba0944..7ed69dfed5f 100644
--- a/lib/init/config-initializer.js
+++ b/lib/init/config-initializer.js
@@ -18,9 +18,13 @@ const util = require("util"),
     semver = require("semver"),
     espree = require("espree"),
     recConfig = require("../../conf/eslint-recommended"),
-    ConfigOps = require("@eslint/eslintrc/lib/shared/config-ops"),
+    {
+        Legacy: {
+            ConfigOps,
+            naming
+        }
+    } = require("@eslint/eslintrc"),
     log = require("../shared/logging"),
-    naming = require("@eslint/eslintrc/lib/shared/naming"),
     ModuleResolver = require("../shared/relative-module-resolver"),
     autoconfig = require("./autoconfig.js"),
     ConfigFile = require("./config-file"),
diff --git a/lib/linter/config-comment-parser.js b/lib/linter/config-comment-parser.js
index 07bbead281c..64482489535 100644
--- a/lib/linter/config-comment-parser.js
+++ b/lib/linter/config-comment-parser.js
@@ -11,7 +11,11 @@
 //------------------------------------------------------------------------------
 
 const levn = require("levn"),
-    ConfigOps = require("@eslint/eslintrc/lib/shared/config-ops");
+    {
+        Legacy: {
+            ConfigOps
+        }
+    } = require("@eslint/eslintrc/universal"); // eslint-disable-line node/no-missing-require -- false positive
 
 const debug = require("debug")("eslint:config-comment-parser");
 
diff --git a/lib/linter/linter.js b/lib/linter/linter.js
index 76a3a2062fe..ae564b6610b 100644
--- a/lib/linter/linter.js
+++ b/lib/linter/linter.js
@@ -16,11 +16,15 @@ const
     evk = require("eslint-visitor-keys"),
     espree = require("espree"),
     merge = require("lodash.merge"),
-    BuiltInEnvironments = require("@eslint/eslintrc/conf/environments"),
     pkg = require("../../package.json"),
     astUtils = require("../shared/ast-utils"),
-    ConfigOps = require("@eslint/eslintrc/lib/shared/config-ops"),
-    ConfigValidator = require("@eslint/eslintrc/lib/shared/config-validator"),
+    {
+        Legacy: {
+            ConfigOps,
+            ConfigValidator,
+            environments: BuiltInEnvironments
+        }
+    } = require("@eslint/eslintrc/universal"), // eslint-disable-line node/no-missing-require -- false positive
     Traverser = require("../shared/traverser"),
     { SourceCode } = require("../source-code"),
     CodePathAnalyzer = require("./code-path-analysis/code-path-analyzer"),
diff --git a/lib/shared/config-validator.js b/lib/shared/config-validator.js
index 03b32f1c918..928d3ce5650 100644
--- a/lib/shared/config-validator.js
+++ b/lib/shared/config-validator.js
@@ -24,9 +24,13 @@
 const
     util = require("util"),
     configSchema = require("../../conf/config-schema"),
-    BuiltInEnvironments = require("@eslint/eslintrc/conf/environments"),
     BuiltInRules = require("../rules"),
-    ConfigOps = require("@eslint/eslintrc/lib/shared/config-ops"),
+    {
+        Legacy: {
+            ConfigOps,
+            environments: BuiltInEnvironments
+        }
+    } = require("@eslint/eslintrc"),
     { emitDeprecationWarning } = require("./deprecation-warnings");
 
 const ajv = require("./ajv")();
diff --git a/package.json b/package.json
index 275554884bd..53c28de3bbc 100644
--- a/package.json
+++ b/package.json
@@ -48,7 +48,7 @@
   "homepage": "https://eslint.org",
   "bugs": "https://github.com/eslint/eslint/issues/",
   "dependencies": {
-    "@eslint/eslintrc": "^0.4.3",
+    "@eslint/eslintrc": "^1.0.0",
     "@humanwhocodes/config-array": "^0.6.0",
     "ajv": "^6.10.0",
     "chalk": "^4.0.0",
diff --git a/tests/_utils/in-memory-fs.js b/tests/_utils/in-memory-fs.js
index ddacfc7bec6..2cf536794c0 100644
--- a/tests/_utils/in-memory-fs.js
+++ b/tests/_utils/in-memory-fs.js
@@ -1,244 +1,11 @@
 /**
- * @fileoverview Define classes what use the in-memory file system.
- *
- * This provides utilities to test `ConfigArrayFactory`,
- * `CascadingConfigArrayFactory`, `FileEnumerator`, `CLIEngine`, and `ESLint`.
- *
- * - `defineConfigArrayFactoryWithInMemoryFileSystem({ cwd, files })`
- * - `defineCascadingConfigArrayFactoryWithInMemoryFileSystem({ cwd, files })`
- * - `defineFileEnumeratorWithInMemoryFileSystem({ cwd, files })`
- * - `defineCLIEngineWithInMemoryFileSystem({ cwd, files })`
- * - `defineESLintWithInMemoryFileSystem({ cwd, files })`
- *
- * Those functions define correspond classes with the in-memory file system.
- * Those search config files, parsers, and plugins in the `files` option via the
- * in-memory file system.
- *
- * For each test case, it makes more readable if we define minimal files the
- * test case requires.
- *
- * For example:
- *
- * ```js
- * const { ConfigArrayFactory } = defineConfigArrayFactoryWithInMemoryFileSystem({
- *     files: {
- *         "node_modules/eslint-config-foo/index.js": `
- *             module.exports = {
- *                 parser: "./parser",
- *                 rules: {
- *                     "no-undef": "error"
- *                 }
- *             }
- *         `,
- *         "node_modules/eslint-config-foo/parser.js": `
- *             module.exports = {
- *                 parse() {}
- *             }
- *         `,
- *         ".eslintrc.json": JSON.stringify({ root: true, extends: "foo" })
- *     }
- * });
- * const factory = new ConfigArrayFactory();
- * const config = factory.loadFile(".eslintrc.json");
- *
- * assert(config[0].name === ".eslintrc.json » eslint-config-foo");
- * assert(config[0].filePath === path.resolve("node_modules/eslint-config-foo/index.js"));
- * assert(config[0].parser.filePath === path.resolve("node_modules/eslint-config-foo/parser.js"));
- *
- * assert(config[1].name === ".eslintrc.json");
- * assert(config[1].filePath === path.resolve(".eslintrc.json"));
- * assert(config[1].root === true);
- * ```
- *
+ * @fileoverview in-memory file system.
  * @author Toru Nagashima <https://github.com/mysticatea>
  */
 "use strict";
 
 const path = require("path");
-const vm = require("vm");
 const { Volume, createFsFromVolume } = require("memfs");
-const Proxyquire = require("proxyquire/lib/proxyquire");
-
-const CascadingConfigArrayFactoryPath =
-    require.resolve("@eslint/eslintrc/lib/cascading-config-array-factory");
-const CLIEnginePath =
-    require.resolve("../../lib/cli-engine/cli-engine");
-const ConfigArrayFactoryPath =
-    require.resolve("@eslint/eslintrc/lib/config-array-factory");
-const FileEnumeratorPath =
-    require.resolve("../../lib/cli-engine/file-enumerator");
-const LoadRulesPath =
-    require.resolve("../../lib/cli-engine/load-rules");
-const ESLintPath =
-    require.resolve("../../lib/eslint/eslint");
-const ESLintAllPath =
-    require.resolve("../../conf/eslint-all");
-const ESLintRecommendedPath =
-    require.resolve("../../conf/eslint-recommended");
-
-// Ensure the needed files has been loaded and cached.
-require(CascadingConfigArrayFactoryPath);
-require(CLIEnginePath);
-require(ConfigArrayFactoryPath);
-require(FileEnumeratorPath);
-require(LoadRulesPath);
-require(ESLintPath);
-require("js-yaml");
-require("espree");
-
-// Override `_require` in order to throw runtime errors in stubs.
-const ERRORED = Symbol("errored");
-const proxyquire = new class extends Proxyquire {
-    _require(...args) {
-        const retv = super._require(...args); // eslint-disable-line no-underscore-dangle
-
-        if (retv[ERRORED]) {
-            throw retv[ERRORED];
-        }
-        return retv;
-    }
-}(module).noCallThru().noPreserveCache();
-
-// Separated (sandbox) context to compile fixture files.
-const context = vm.createContext();
-
-/**
- * Check if a given path is an existing file.
- * @param {import("fs")} fs The file system.
- * @param {string} filePath Tha path to a file to check.
- * @returns {boolean} `true` if the file existed.
- */
-function isExistingFile(fs, filePath) {
-    try {
-        return fs.statSync(filePath).isFile();
-    } catch {
-        return false;
-    }
-}
-
-/**
- * Get some paths to test.
- * @param {string} prefix The prefix to try.
- * @returns {string[]} The paths to test.
- */
-function getTestPaths(prefix) {
-    return [
-        path.join(prefix),
-        path.join(`${prefix}.js`),
-        path.join(prefix, "index.js")
-    ];
-}
-
-/**
- * Iterate the candidate paths of a given request to resolve.
- * @param {string} request Tha package name or file path to resolve.
- * @param {string} relativeTo Tha path to the file what called this resolving.
- * @returns {IterableIterator<string>} The candidate paths.
- */
-function *iterateCandidatePaths(request, relativeTo) {
-    if (path.isAbsolute(request)) {
-        yield* getTestPaths(request);
-        return;
-    }
-    if (/^\.{1,2}[/\\]/u.test(request)) {
-        yield* getTestPaths(path.resolve(path.dirname(relativeTo), request));
-        return;
-    }
-
-    let prevPath = path.resolve(relativeTo);
-    let dirPath = path.dirname(prevPath);
-
-    while (dirPath && dirPath !== prevPath) {
-        yield* getTestPaths(path.join(dirPath, "node_modules", request));
-        prevPath = dirPath;
-        dirPath = path.dirname(dirPath);
-    }
-}
-
-/**
- * Resolve a given module name or file path relatively in the given file system.
- * @param {import("fs")} fs The file system.
- * @param {string} request Tha package name or file path to resolve.
- * @param {string} relativeTo Tha path to the file what called this resolving.
- * @returns {void}
- */
-function fsResolve(fs, request, relativeTo) {
-    for (const filePath of iterateCandidatePaths(request, relativeTo)) {
-        if (isExistingFile(fs, filePath)) {
-            return filePath;
-        }
-    }
-
-    throw Object.assign(
-        new Error(`Cannot find module '${request}'`),
-        { code: "MODULE_NOT_FOUND" }
-    );
-}
-
-/**
- * Compile a JavaScript file.
- * This is used to compile only fixture files, so this is minimam.
- * @param {import("fs")} fs The file system.
- * @param {Object} stubs The stubs.
- * @param {string} filePath The path to a JavaScript file to compile.
- * @param {string} content The source code to compile.
- * @returns {any} The exported value.
- */
-function compile(fs, stubs, filePath, content) {
-    const code = `(function(exports, require, module, __filename, __dirname) { ${content} })`;
-    const f = vm.runInContext(code, context);
-    const exports = {};
-    const module = { exports };
-
-    f.call(
-        exports,
-        exports,
-        request => {
-            const modulePath = fsResolve(fs, request, filePath);
-            const stub = stubs[modulePath];
-
-            if (stub[ERRORED]) {
-                throw stub[ERRORED];
-            }
-            return stub;
-        },
-        module,
-        filePath,
-        path.dirname(filePath)
-    );
-
-    return module.exports;
-}
-
-/**
- * Import a given file path in the given file system.
- * @param {import("fs")} fs The file system.
- * @param {Object} stubs The stubs.
- * @param {string} absolutePath Tha file path to import.
- * @returns {void}
- */
-function fsImportFresh(fs, stubs, absolutePath) {
-    if (absolutePath === ESLintAllPath) {
-        return require(ESLintAllPath);
-    }
-    if (absolutePath === ESLintRecommendedPath) {
-        return require(ESLintRecommendedPath);
-    }
-
-    if (fs.existsSync(absolutePath)) {
-        return compile(
-            fs,
-            stubs,
-            absolutePath,
-            fs.readFileSync(absolutePath, "utf8")
-        );
-    }
-
-    throw Object.assign(
-        new Error(`Cannot find module '${absolutePath}'`),
-        { code: "MODULE_NOT_FOUND" }
-    );
-}
 
 /**
  * Define in-memory file system.
@@ -285,257 +52,6 @@ function defineInMemoryFs({
     return fs;
 }
 
-/**
- * Define stubbed `ConfigArrayFactory` class what uses the in-memory file system.
- * @param {Object} options The options.
- * @param {() => string} [options.cwd] The current working directory.
- * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"] }} The stubbed `ConfigArrayFactory` class.
- */
-function defineConfigArrayFactoryWithInMemoryFileSystem({
-    cwd = process.cwd,
-    files = {}
-} = {}) {
-    const fs = defineInMemoryFs({ cwd, files });
-    const RelativeModuleResolver = { resolve: fsResolve.bind(null, fs) };
-
-    /*
-     * Stubs for proxyquire.
-     * This contains the JavaScript files in `options.files`.
-     */
-    const stubs = {};
-
-    stubs.fs = fs;
-    stubs["import-fresh"] = fsImportFresh.bind(null, fs, stubs);
-    stubs["../shared/relative-module-resolver"] = RelativeModuleResolver;
-
-    /*
-     * Write all files to the in-memory file system and compile all JavaScript
-     * files then set to `stubs`.
-     */
-    (function initFiles(directoryPath, definition) {
-        for (const [filename, content] of Object.entries(definition)) {
-            const filePath = path.resolve(directoryPath, filename);
-
-            if (typeof content === "object") {
-                initFiles(filePath, content);
-                continue;
-            }
-
-            /*
-             * Compile then stub if this file is a JavaScript file.
-             * For parsers and plugins that `require()` will import.
-             */
-            if (path.extname(filePath) === ".js") {
-                Object.defineProperty(stubs, filePath, {
-                    configurable: true,
-                    enumerable: true,
-                    get() {
-                        let stub;
-
-                        try {
-                            stub = compile(fs, stubs, filePath, content);
-                        } catch (error) {
-                            stub = { [ERRORED]: error };
-                        }
-                        Object.defineProperty(stubs, filePath, {
-                            configurable: true,
-                            enumerable: true,
-                            value: stub
-                        });
-
-                        return stub;
-                    }
-                });
-            }
-        }
-    }(cwd(), files));
-
-    // Load the stubbed one.
-    const { ConfigArrayFactory } = proxyquire(ConfigArrayFactoryPath, stubs);
-
-    // Override the default cwd.
-    return {
-        fs,
-        stubs,
-        RelativeModuleResolver,
-        ConfigArrayFactory: cwd === process.cwd
-            ? ConfigArrayFactory
-            : class extends ConfigArrayFactory {
-                constructor(options) {
-                    super({ cwd: cwd(), ...options });
-                }
-            }
-    };
-}
-
-/**
- * Define stubbed `CascadingConfigArrayFactory` class what uses the in-memory file system.
- * @param {Object} options The options.
- * @param {() => string} [options.cwd] The current working directory.
- * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"], CascadingConfigArrayFactory: import("../../../lib/cli-engine/cascading-config-array-factory")["CascadingConfigArrayFactory"] }} The stubbed `CascadingConfigArrayFactory` class.
- */
-function defineCascadingConfigArrayFactoryWithInMemoryFileSystem({
-    cwd = process.cwd,
-    files = {}
-} = {}) {
-    const { fs, stubs, RelativeModuleResolver, ConfigArrayFactory } =
-           defineConfigArrayFactoryWithInMemoryFileSystem({ cwd, files });
-    const loadRules = proxyquire(LoadRulesPath, stubs);
-    const { CascadingConfigArrayFactory } =
-        proxyquire(CascadingConfigArrayFactoryPath, {
-            "./config-array-factory": { ConfigArrayFactory },
-            "./load-rules": loadRules
-        });
-
-    // Override the default cwd.
-    return {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory: cwd === process.cwd
-            ? CascadingConfigArrayFactory
-            : class extends CascadingConfigArrayFactory {
-                constructor(options) {
-                    super({ cwd: cwd(), ...options });
-                }
-            }
-    };
-}
-
-/**
- * Define stubbed `FileEnumerator` class what uses the in-memory file system.
- * @param {Object} options The options.
- * @param {() => string} [options.cwd] The current working directory.
- * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"], CascadingConfigArrayFactory: import("../../../lib/cli-engine/cascading-config-array-factory")["CascadingConfigArrayFactory"], FileEnumerator: import("../../../lib/cli-engine/file-enumerator")["FileEnumerator"] }} The stubbed `FileEnumerator` class.
- */
-function defineFileEnumeratorWithInMemoryFileSystem({
-    cwd = process.cwd,
-    files = {}
-} = {}) {
-    const {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory
-    } =
-        defineCascadingConfigArrayFactoryWithInMemoryFileSystem({ cwd, files });
-    const { FileEnumerator } = proxyquire(FileEnumeratorPath, {
-        fs,
-        "./cascading-config-array-factory": { CascadingConfigArrayFactory }
-    });
-
-    // Override the default cwd.
-    return {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory,
-        FileEnumerator: cwd === process.cwd
-            ? FileEnumerator
-            : class extends FileEnumerator {
-                constructor(options) {
-                    super({ cwd: cwd(), ...options });
-                }
-            }
-    };
-}
-
-/**
- * Define stubbed `CLIEngine` class what uses the in-memory file system.
- * @param {Object} options The options.
- * @param {() => string} [options.cwd] The current working directory.
- * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"], CascadingConfigArrayFactory: import("../../../lib/cli-engine/cascading-config-array-factory")["CascadingConfigArrayFactory"], FileEnumerator: import("../../../lib/cli-engine/file-enumerator")["FileEnumerator"], CLIEngine: import("../../../lib/cli-engine/cli-engine")["CLIEngine"], getCLIEngineInternalSlots: import("../../../lib/cli-engine/cli-engine")["getCLIEngineInternalSlots"] }} The stubbed `CLIEngine` class.
- */
-function defineCLIEngineWithInMemoryFileSystem({
-    cwd = process.cwd,
-    files = {}
-} = {}) {
-    const {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory,
-        FileEnumerator
-    } =
-        defineFileEnumeratorWithInMemoryFileSystem({ cwd, files });
-    const { CLIEngine, getCLIEngineInternalSlots } = proxyquire(CLIEnginePath, {
-        fs,
-        "./cascading-config-array-factory": { CascadingConfigArrayFactory },
-        "./file-enumerator": { FileEnumerator },
-        "../shared/relative-module-resolver": RelativeModuleResolver
-    });
-
-    // Override the default cwd.
-    return {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory,
-        FileEnumerator,
-        CLIEngine: cwd === process.cwd
-            ? CLIEngine
-            : class extends CLIEngine {
-                constructor(options) {
-                    super({ cwd: cwd(), ...options });
-                }
-            },
-        getCLIEngineInternalSlots
-    };
-}
-
-/**
- * Define stubbed `ESLint` class that uses the in-memory file system.
- * @param {Object} options The options.
- * @param {() => string} [options.cwd] The current working directory.
- * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"], CascadingConfigArrayFactory: import("../../lib/cli-engine/cascading-config-array-factory")["CascadingConfigArrayFactory"], FileEnumerator: import("../../lib/cli-engine/file-enumerator")["FileEnumerator"], ESLint: import("../../lib/eslint/eslint")["ESLint"], getCLIEngineInternalSlots: import("../../lib//eslint/eslint")["getESLintInternalSlots"] }} The stubbed `ESLint` class.
- */
-function defineESLintWithInMemoryFileSystem({
-    cwd = process.cwd,
-    files = {}
-} = {}) {
-    const {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory,
-        FileEnumerator,
-        CLIEngine,
-        getCLIEngineInternalSlots
-    } = defineCLIEngineWithInMemoryFileSystem({ cwd, files });
-    const { ESLint, getESLintPrivateMembers } = proxyquire(ESLintPath, {
-        "../cli-engine/cli-engine": { CLIEngine, getCLIEngineInternalSlots }
-    });
-
-    // Override the default cwd.
-    return {
-        fs,
-        RelativeModuleResolver,
-        ConfigArrayFactory,
-        CascadingConfigArrayFactory,
-        FileEnumerator,
-        CLIEngine,
-        getCLIEngineInternalSlots,
-        ESLint: cwd === process.cwd
-            ? ESLint
-            : class extends ESLint {
-                constructor(options) {
-                    super({ cwd: cwd(), ...options });
-                }
-            },
-        getESLintPrivateMembers
-    };
-}
-
 module.exports = {
-    defineInMemoryFs,
-    defineConfigArrayFactoryWithInMemoryFileSystem,
-    defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
-    defineFileEnumeratorWithInMemoryFileSystem,
-    defineCLIEngineWithInMemoryFileSystem,
-    defineESLintWithInMemoryFileSystem
+    defineInMemoryFs
 };
diff --git a/tests/_utils/index.js b/tests/_utils/index.js
index 7615613d25c..08ef08ae690 100644
--- a/tests/_utils/index.js
+++ b/tests/_utils/index.js
@@ -9,12 +9,7 @@
 //-----------------------------------------------------------------------------
 
 const {
-    defineInMemoryFs,
-    defineConfigArrayFactoryWithInMemoryFileSystem,
-    defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
-    defineFileEnumeratorWithInMemoryFileSystem,
-    defineCLIEngineWithInMemoryFileSystem,
-    defineESLintWithInMemoryFileSystem
+    defineInMemoryFs
 } = require("./in-memory-fs");
 
 const { createTeardown, addFile } = require("fs-teardown");
@@ -64,10 +59,5 @@ function createCustomTeardown({ cwd, files }) {
 module.exports = {
     unIndent,
     defineInMemoryFs,
-    defineConfigArrayFactoryWithInMemoryFileSystem,
-    defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
-    defineFileEnumeratorWithInMemoryFileSystem,
-    defineCLIEngineWithInMemoryFileSystem,
-    defineESLintWithInMemoryFileSystem,
     createCustomTeardown
 };
diff --git a/tests/lib/cli-engine/cli-engine.js b/tests/lib/cli-engine/cli-engine.js
index b7a82ff2209..431437e4fd1 100644
--- a/tests/lib/cli-engine/cli-engine.js
+++ b/tests/lib/cli-engine/cli-engine.js
@@ -16,7 +16,11 @@ const assert = require("chai").assert,
     fs = require("fs"),
     os = require("os"),
     hash = require("../../../lib/cli-engine/hash"),
-    { CascadingConfigArrayFactory } = require("@eslint/eslintrc/lib/cascading-config-array-factory"),
+    {
+        Legacy: {
+            CascadingConfigArrayFactory
+        }
+    } = require("@eslint/eslintrc"),
     { unIndent, createCustomTeardown } = require("../../_utils");
 
 const proxyquire = require("proxyquire").noCallThru().noPreserveCache();
diff --git a/tests/lib/cli-engine/file-enumerator.js b/tests/lib/cli-engine/file-enumerator.js
index 1ea7a3bd2c4..a2ad62e4e27 100644
--- a/tests/lib/cli-engine/file-enumerator.js
+++ b/tests/lib/cli-engine/file-enumerator.js
@@ -9,8 +9,11 @@ const path = require("path");
 const os = require("os");
 const { assert } = require("chai");
 const sh = require("shelljs");
-const { CascadingConfigArrayFactory } =
-    require("@eslint/eslintrc/lib/cascading-config-array-factory");
+const {
+    Legacy: {
+        CascadingConfigArrayFactory
+    }
+} = require("@eslint/eslintrc");
 const { createCustomTeardown } = require("../../_utils");
 const { FileEnumerator } = require("../../../lib/cli-engine/file-enumerator");
 
diff --git a/tests/lib/eslint/eslint.js b/tests/lib/eslint/eslint.js
index 0a5b5e1a9a4..a5e342f0dca 100644
--- a/tests/lib/eslint/eslint.js
+++ b/tests/lib/eslint/eslint.js
@@ -19,7 +19,11 @@ const fCache = require("file-entry-cache");
 const sinon = require("sinon");
 const proxyquire = require("proxyquire").noCallThru().noPreserveCache();
 const shell = require("shelljs");
-const { CascadingConfigArrayFactory } = require("@eslint/eslintrc/lib/cascading-config-array-factory");
+const {
+    Legacy: {
+        CascadingConfigArrayFactory
+    }
+} = require("@eslint/eslintrc");
 const hash = require("../../../lib/cli-engine/hash");
 const { unIndent, createCustomTeardown } = require("../../_utils");
 const coreRules = require("../../../lib/rules");