diff --git a/test/esm-helpers.mjs b/test/esm-helpers.mjs
new file mode 100644
index 0000000..fdf0b6e
--- /dev/null
+++ b/test/esm-helpers.mjs
@@ -0,0 +1,19 @@
+// @ts-check
+
+import fs from "node:fs/promises";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+// Shims import.meta.filename on Node 18
+// eslint-disable-next-line no-underscore-dangle
+export const __filename = (meta) => fileURLToPath(meta.url);
+
+// Shims import.meta.dirname on Node 18
+// eslint-disable-next-line no-underscore-dangle
+export const __dirname = (meta) => path.dirname(__filename(meta));
+
+// Avoids "ExperimentalWarning: Importing JSON modules is an experimental feature and might change at any time"
+export const importWithTypeJson = async (file) => (
+  // @ts-ignore
+  JSON.parse(await fs.readFile(path.resolve(__dirname(import.meta), file)))
+);
diff --git a/test/fs-mock-test.mjs b/test/fs-mock-test.mjs
index f8f5cde..4b25de9 100644
--- a/test/fs-mock-test.mjs
+++ b/test/fs-mock-test.mjs
@@ -4,15 +4,16 @@ import fsNodePromises from "node:fs/promises";
 import path from "node:path";
 import { promisify } from "node:util";
 import test from "ava";
+import { __dirname, __filename } from "./esm-helpers.mjs";
 import FsMock from "./fs-mock.mjs";
 
 const mockPath = "/mock";
-const thisFile = path.basename(import.meta.filename);
+const thisFile = path.basename(__filename(import.meta));
 const testFile = path.join(mockPath, thisFile);
 
 test("fsMock.stat", async (t) => {
   t.plan(2);
-  const fs = new FsMock(import.meta.dirname);
+  const fs = new FsMock(__dirname(import.meta));
   const fsStat = promisify(fs.stat);
   // @ts-ignore
   const stat = await fsStat(testFile);
@@ -22,7 +23,7 @@ test("fsMock.stat", async (t) => {
 
 test("fsMock.lstat", async (t) => {
   t.plan(3);
-  const fs = new FsMock(import.meta.dirname);
+  const fs = new FsMock(__dirname(import.meta));
   const fsLstat = promisify(fs.lstat);
   // @ts-ignore
   const stat = await fsLstat(testFile);
@@ -33,7 +34,7 @@ test("fsMock.lstat", async (t) => {
 
 test("fsMock.lstat symbolic links", async (t) => {
   t.plan(3);
-  const fs = new FsMock(import.meta.dirname, true);
+  const fs = new FsMock(__dirname(import.meta), true);
   const fsLstat = promisify(fs.lstat);
   // @ts-ignore
   const stat = await fsLstat(testFile);
@@ -44,7 +45,7 @@ test("fsMock.lstat symbolic links", async (t) => {
 
 test("fsMock.readdir", async (t) => {
   t.plan(3);
-  const fs = new FsMock(import.meta.dirname);
+  const fs = new FsMock(__dirname(import.meta));
   const fsReaddir = promisify(fs.readdir);
   // @ts-ignore
   const files = await fsReaddir(mockPath);
@@ -55,7 +56,7 @@ test("fsMock.readdir", async (t) => {
 
 test("fsMock.*", async (t) => {
   t.plan(1);
-  const fs = new FsMock(import.meta.dirname);
+  const fs = new FsMock(__dirname(import.meta));
   const fsAccess = promisify(fs.access);
   // @ts-ignore
   await fsAccess(testFile);
@@ -73,7 +74,7 @@ test("fsMock.*", async (t) => {
 
 test("fsMock.promises.*", async (t) => {
   t.plan(2);
-  const fs = new FsMock(import.meta.dirname);
+  const fs = new FsMock(__dirname(import.meta));
   const tempName = "fs-mock.tmp";
   const tempFile = path.join(mockPath, tempName);
   await t.throwsAsync(() => fs.promises.access(tempFile));
@@ -81,5 +82,5 @@ test("fsMock.promises.*", async (t) => {
   await fs.promises.access(tempFile);
   await fs.promises.stat(tempFile);
   t.is(await fs.promises.readFile(tempFile, "utf8"), tempFile);
-  await fsNodePromises.unlink(path.join(import.meta.dirname, tempName));
+  await fsNodePromises.unlink(path.join(__dirname(import.meta), tempName));
 });
diff --git a/test/fs-virtual-test.mjs b/test/fs-virtual-test.mjs
index cf50407..88860c7 100644
--- a/test/fs-virtual-test.mjs
+++ b/test/fs-virtual-test.mjs
@@ -3,10 +3,11 @@
 import path from "node:path";
 import { promisify } from "node:util";
 import test from "ava";
+import { __filename } from "./esm-helpers.mjs";
 import FsVirtual from "../webworker/fs-virtual.mjs";
 
 const mockPath = "/mock";
-const thisFile = path.basename(import.meta.filename);
+const thisFile = path.basename(__filename(import.meta));
 const testFile = path.join(mockPath, thisFile);
 const missingFile = `${mockPath}/missing`;
 
diff --git a/test/import-with-type-json.mjs b/test/import-with-type-json.mjs
deleted file mode 100644
index 60521e2..0000000
--- a/test/import-with-type-json.mjs
+++ /dev/null
@@ -1,12 +0,0 @@
-// @ts-check
-
-import fs from "node:fs/promises";
-import path from "node:path";
-
-// Avoids "ExperimentalWarning: Importing JSON modules is an experimental feature and might change at any time"
-const importWithTypeJson = async (file) => (
-  // @ts-ignore
-  JSON.parse(await fs.readFile(path.resolve(import.meta.dirname, file)))
-);
-
-export default importWithTypeJson;
diff --git a/test/markdownlint-cli2-test-cases.mjs b/test/markdownlint-cli2-test-cases.mjs
index b4c3453..ac654fa 100644
--- a/test/markdownlint-cli2-test-cases.mjs
+++ b/test/markdownlint-cli2-test-cases.mjs
@@ -4,6 +4,7 @@ import fs from "node:fs/promises";
 import os from "node:os";
 import path from "node:path";
 import test from "ava";
+import { __dirname } from "./esm-helpers.mjs";
 
 const noop = () => null;
 const empty = () => "";
@@ -11,7 +12,7 @@ const sanitize = (str) => str.
   replace(/\r/gu, "").
   replace(/\bv\d+\.\d+\.\d+\b/gu, "vX.Y.Z").
   replace(/ :.+[/\\]sentinel/gu, " :[PATH]");
-const sameFileSystem = (path.relative(os.homedir(), import.meta.dirname) !== import.meta.dirname);
+const sameFileSystem = (path.relative(os.homedir(), __dirname(import.meta)) !== __dirname(import.meta));
 const isModule = (file) => file.endsWith(".cjs") || file.endsWith(".mjs");
 
 const testCases = ({
@@ -55,7 +56,7 @@ const testCases = ({
     }
     test(`${name} (${host})`, (t) => {
       t.plan(3);
-      const directory = path.join(import.meta.dirname, cwd || name);
+      const directory = path.join(__dirname(import.meta), cwd || name);
       return ((pre || noop)(name, shadow) || Promise.resolve()).
         then(invoke(directory, args, noRequire, env, script)).
         then((result) => Promise.all([
@@ -141,13 +142,13 @@ const testCases = ({
 
   const copyDirectory = (dir, alt) => import("cpy").then((cpy) => (
     cpy.default(
-      path.join(import.meta.dirname, (alt || dir), "**"),
-      path.join(import.meta.dirname, directoryName(dir))
+      path.join(__dirname(import.meta), (alt || dir), "**"),
+      path.join(__dirname(import.meta), directoryName(dir))
     )
   ));
 
   const deleteDirectory = (dir) => import("del").then((del) => (
-    del.deleteAsync(path.join(import.meta.dirname, directoryName(dir)))
+    del.deleteAsync(path.join(__dirname(import.meta), directoryName(dir)))
   ));
 
   testCase({
@@ -586,7 +587,7 @@ const testCases = ({
   });
 
   const literalFilesAbsoluteFile = absolute(
-    path.join(import.meta.dirname, "literal-files"),
+    path.join(__dirname(import.meta), "literal-files"),
     "sentinel/dir(1)/(view)me.md"
   ).
     split(path.sep).
@@ -668,7 +669,7 @@ const testCases = ({
       "name": `config-files-${configFile}-absolute-arg`,
       "args": [
         "--config",
-        path.join(import.meta.dirname, "config-files", `cfg/${configFile}`),
+        path.join(__dirname(import.meta), "config-files", `cfg/${configFile}`),
         "**/*.md"
       ],
       "exitCode": 1,
diff --git a/test/markdownlint-cli2-test-exec.mjs b/test/markdownlint-cli2-test-exec.mjs
index 78f5420..5285c55 100644
--- a/test/markdownlint-cli2-test-exec.mjs
+++ b/test/markdownlint-cli2-test-exec.mjs
@@ -4,9 +4,10 @@ import fs from "node:fs/promises";
 import path from "node:path";
 import test from "ava";
 import testCases from "./markdownlint-cli2-test-cases.mjs";
+import { __dirname } from "./esm-helpers.mjs";
 
 const absolute = (rootDir, file) => path.join(rootDir, file);
-const repositoryPath = (name) => path.join(import.meta.dirname, "..", name);
+const repositoryPath = (name) => path.join(__dirname(import.meta), "..", name);
 
 const invoke = (directory, args, noRequire, env, script) => async () => {
   await fs.access(directory);
@@ -158,7 +159,7 @@ test("- parameter uses base directory configuration", (t) => {
   return invokeStdin(
     [ "-" ],
     invalidInput,
-    path.join(import.meta.dirname, "stdin")
+    path.join(__dirname(import.meta), "stdin")
   ).
     then(() => t.fail()).
     catch((error) => {
@@ -172,7 +173,7 @@ test("- parameter not treated as stdin in configuration file globs", (t) => {
   return invokeStdin(
     [],
     invalidInput,
-    path.join(import.meta.dirname, "stdin-globs")
+    path.join(__dirname(import.meta), "stdin-globs")
   ).
     then(() => t.pass()).
     catch(() => t.fail());
diff --git a/test/markdownlint-cli2-test-exports.mjs b/test/markdownlint-cli2-test-exports.mjs
index 4934515..951ab87 100644
--- a/test/markdownlint-cli2-test-exports.mjs
+++ b/test/markdownlint-cli2-test-exports.mjs
@@ -1,7 +1,7 @@
 // @ts-check
 
 import test from "ava";
-import importWithTypeJson from "./import-with-type-json.mjs";
+import { importWithTypeJson } from "./esm-helpers.mjs";
 const packageJson = await importWithTypeJson("../package.json");
 
 const exportMappings = new Map([
diff --git a/test/markdownlint-cli2-test.mjs b/test/markdownlint-cli2-test.mjs
index b4f2554..fbf43b6 100644
--- a/test/markdownlint-cli2-test.mjs
+++ b/test/markdownlint-cli2-test.mjs
@@ -6,7 +6,7 @@ import path from "node:path";
 import Ajv from "ajv";
 import test from "ava";
 import { globby } from "globby";
-import importWithTypeJson from "./import-with-type-json.mjs";
+import { __dirname, importWithTypeJson } from "./esm-helpers.mjs";
 const packageJson = await importWithTypeJson("../package.json");
 import { "main" as markdownlintCli2 } from "../markdownlint-cli2.mjs";
 import jsoncParse from "../parsers/jsonc-parse.mjs";
@@ -294,7 +294,7 @@ test("alternate file contents with ignores", (t) => {
 test("extension scenario, file, no changes", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": import.meta.dirname,
+    "directory": __dirname(import.meta),
     "argv": [ ":./markdownlint-json/viewme.md" ],
     "optionsOverride": {
       "outputFormatters": [ [ outputFormatterLengthIs(t, 4) ] ]
@@ -306,7 +306,7 @@ test("extension scenario, file, no changes", (t) => {
 test("extension scenario, file, changes", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": import.meta.dirname,
+    "directory": __dirname(import.meta),
     "argv": [ ":./markdownlint-json/viewme.md" ],
     "fileContents": {
       "./markdownlint-json/viewme.md": "# Title\n\n> Tagline \n\n\n"
@@ -321,7 +321,7 @@ test("extension scenario, file, changes", (t) => {
 test("extension scenario, no file", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": import.meta.dirname,
+    "directory": __dirname(import.meta),
     "argv": [],
     "nonFileContents": {
       "untitled-1": "# Title\n\nText\t\n"
@@ -336,7 +336,7 @@ test("extension scenario, no file", (t) => {
 test("extension scenario, no file, empty", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": import.meta.dirname,
+    "directory": __dirname(import.meta),
     "argv": [],
     "nonFileContents": {
       "untitled-1": ""
@@ -360,7 +360,7 @@ test("extension scenario, ignores handled", (t) => {
   };
   const argv = Object.keys(fileContents).map((key) => `:${key}`);
   return markdownlintCli2({
-    "directory": path.join(import.meta.dirname, "extension-scenario-ignores"),
+    "directory": path.join(__dirname(import.meta), "extension-scenario-ignores"),
     argv,
     fileContents,
     "optionsOverride": {
@@ -372,7 +372,7 @@ test("extension scenario, ignores handled", (t) => {
 
 test("extension scenario, ignores handled, absolute paths", (t) => {
   t.plan(2);
-  const directory = path.join(import.meta.dirname, "extension-scenario-ignores");
+  const directory = path.join(__dirname(import.meta), "extension-scenario-ignores");
   const fileContents = Object.fromEntries(
     Object.entries({
       "viewme.md": "Heading",
@@ -401,7 +401,7 @@ test("extension scenario, ignores handled, absolute paths", (t) => {
 test("extension scenario, globs ignored/filtered", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": path.join(import.meta.dirname, "extension-scenario-globs"),
+    "directory": path.join(__dirname(import.meta), "extension-scenario-globs"),
     "argv": [
       ":viewme.md",
       ":dir/viewme.md",
@@ -425,14 +425,14 @@ test("extension scenario, globs ignored/filtered", (t) => {
 test("backslash translation", (t) => {
   t.plan(2);
   return markdownlintCli2({
-    "directory": import.meta.dirname,
+    "directory": __dirname(import.meta),
     "argv": [
       "./markdownlint-json/viewme.md",
       "markdownlint-jsonc/viewme.md",
-      path.join(import.meta.dirname, "markdownlint-cli2-jsonc/viewme.md"),
+      path.join(__dirname(import.meta), "markdownlint-cli2-jsonc/viewme.md"),
       ".\\markdownlint-yml\\viewme.md",
       "markdownlint-yaml\\viewme.md",
-      path.join(import.meta.dirname, "markdownlint-cli2-yaml\\viewme.md")
+      path.join(__dirname(import.meta), "markdownlint-cli2-yaml\\viewme.md")
     ],
     "optionsOverride": {
       "outputFormatters": [ [ outputFormatterLengthIs(t, 24) ] ]
@@ -610,7 +610,7 @@ test("custom fs, using fsMock", (t) => {
     "optionsOverride": {
       "outputFormatters": [ [ outputFormatterLengthIs(t, 10) ] ]
     },
-    "fs": new FsMock(path.join(import.meta.dirname, "markdownlint-cli2-jsonc")),
+    "fs": new FsMock(path.join(__dirname(import.meta), "markdownlint-cli2-jsonc")),
     "noRequire": true
   }).
     then((exitCode) => {
@@ -626,7 +626,7 @@ test("custom fs, using fsMock simulating symbolic links", (t) => {
     "optionsOverride": {
       "outputFormatters": [ [ outputFormatterLengthIs(t, 10) ] ]
     },
-    "fs": new FsMock(path.join(import.meta.dirname, "markdownlint-cli2-jsonc"), true),
+    "fs": new FsMock(path.join(__dirname(import.meta), "markdownlint-cli2-jsonc"), true),
     "noRequire": true
   }).
     then((exitCode) => {
diff --git a/test/resolve-and-require-test.mjs b/test/resolve-and-require-test.mjs
index cfeb23e..97897f6 100644
--- a/test/resolve-and-require-test.mjs
+++ b/test/resolve-and-require-test.mjs
@@ -2,6 +2,7 @@
 
 import test from "ava";
 import path from "node:path";
+import { __dirname } from "./esm-helpers.mjs";
 import resolveAndRequire from "../resolve-and-require.mjs";
 
 import { createRequire } from "node:module";
@@ -11,7 +12,7 @@ test("built-in module", (t) => {
   t.plan(1);
   t.deepEqual(
     require("node:fs"),
-    resolveAndRequire(require, "fs", [ import.meta.dirname ])
+    resolveAndRequire(require, "fs", [ __dirname(import.meta) ])
   );
 });
 
@@ -19,18 +20,18 @@ test("locally-installed module", (t) => {
   t.plan(1);
   t.deepEqual(
     require("markdownlint"),
-    resolveAndRequire(require, "markdownlint", [ import.meta.dirname ])
+    resolveAndRequire(require, "markdownlint", [ __dirname(import.meta) ])
   );
 });
 
-test("relative (to import.meta.dirname) path to module", (t) => {
+test("relative (to __dirname(import.meta)) path to module", (t) => {
   t.plan(1);
   t.deepEqual(
     require("./customRules/node_modules/markdownlint-rule-sample-commonjs"),
     resolveAndRequire(
       require,
       "./customRules/node_modules/markdownlint-rule-sample-commonjs",
-      [ import.meta.dirname ]
+      [ __dirname(import.meta) ]
     )
   );
 });
@@ -47,7 +48,7 @@ test("module in alternate node_modules", (t) => {
     resolveAndRequire(
       require,
       "markdownlint-rule-sample-commonjs",
-      [ path.join(import.meta.dirname, "customRules") ]
+      [ path.join(__dirname(import.meta), "customRules") ]
     )
   );
 });
@@ -66,7 +67,7 @@ test("module in alternate node_modules and no require.resolve.paths", (t) => {
     resolveAndRequire(
       require,
       "markdownlint-rule-sample-commonjs",
-      [ path.join(import.meta.dirname, "customRules") ]
+      [ path.join(__dirname(import.meta), "customRules") ]
     )
   );
 });
@@ -74,8 +75,8 @@ test("module in alternate node_modules and no require.resolve.paths", (t) => {
 test("module local, relative, and in alternate node_modules", (t) => {
   t.plan(3);
   const dirs = [
-    import.meta.dirname,
-    path.join(import.meta.dirname, "customRules")
+    __dirname(import.meta),
+    path.join(__dirname(import.meta), "customRules")
   ];
   t.deepEqual(
     require("markdownlint"),