diff --git a/CHANGES.md b/CHANGES.md
index edd1562..7572638 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -8,8 +8,13 @@ Version 0.4.2
 
 To be released.
 
- -  The npm version of LogTape no more depends on `node:stream/web` module.
-    This should make it easier to use LogTape on edge functions.
+ -  LogTape now works well on edge functions.  [[#5]]
+
+     -  The npm version of LogTape no more depends on `node:stream/web` module.
+     -  LogTape now works well with JavaScript runtimes that do not support
+        `node:fs` module.
+
+[#5]: https://github.com/dahlia/logtape/issues/5
 
 
 Version 0.4.1
diff --git a/dnt.ts b/dnt.ts
index 12fe26d..2b71189 100644
--- a/dnt.ts
+++ b/dnt.ts
@@ -31,6 +31,7 @@ await build({
   mappings: {
     "./logtape/filesink.jsr.ts": "./logtape/filesink.node.ts",
     "./logtape/filesink.deno.ts": "./logtape/filesink.node.ts",
+    "./logtape/fs.ts": "./logtape/fs.js",
   },
   shims: {
     deno: "dev",
@@ -42,6 +43,8 @@ await build({
     lib: ["ES2021", "DOM"],
   },
   async postBuild() {
+    await Deno.copyFile("logtape/fs.mjs", "npm/esm/fs.js");
+    await Deno.copyFile("logtape/fs.cjs", "npm/script/fs.js");
     await Deno.copyFile("LICENSE", "npm/LICENSE");
     await Deno.copyFile("README.md", "npm/README.md");
   },
diff --git a/logtape/filesink.node.ts b/logtape/filesink.node.ts
index f2e78a3..8cf65ae 100644
--- a/logtape/filesink.node.ts
+++ b/logtape/filesink.node.ts
@@ -1,4 +1,6 @@
-import fs from "node:fs";
+// @ts-ignore: a trick to avoid module resolution error on non-Node.js environ
+import fsMod from "./fs.ts";
+import type fsType from "node:fs";
 import { webDriver } from "./filesink.web.ts";
 import {
   type FileSinkOptions,
@@ -9,19 +11,24 @@ import {
   type Sink,
 } from "./sink.ts";
 
+// @ts-ignore: a trick to avoid module resolution error on non-Node.js environ
+const fs = fsMod as (typeof fsType | null);
+
 /**
  * A Node.js-specific file sink driver.
  */
-export const nodeDriver: RotatingFileSinkDriver<number> = {
-  openSync(path: string) {
-    return fs.openSync(path, "a");
-  },
-  writeSync: fs.writeSync,
-  flushSync: fs.fsyncSync,
-  closeSync: fs.closeSync,
-  statSync: fs.statSync,
-  renameSync: fs.renameSync,
-};
+export const nodeDriver: RotatingFileSinkDriver<number | void> = fs == null
+  ? webDriver
+  : {
+    openSync(path: string) {
+      return fs.openSync(path, "a");
+    },
+    writeSync: fs.writeSync,
+    flushSync: fs.fsyncSync,
+    closeSync: fs.closeSync,
+    statSync: fs.statSync,
+    renameSync: fs.renameSync,
+  };
 
 /**
  * Get a file sink.
diff --git a/logtape/fs.cjs b/logtape/fs.cjs
new file mode 100644
index 0000000..bcb0170
--- /dev/null
+++ b/logtape/fs.cjs
@@ -0,0 +1,16 @@
+let fs = null;
+if (
+  "process" in globalThis && "versions" in globalThis.process &&
+    "node" in globalThis.process.versions &&
+    typeof globalThis.caches === "undefined" &&
+    typeof globalThis.addEventListener !== "function" ||
+  "Bun" in globalThis
+) {
+  try {
+    fs = require("node" + ":fs");
+  } catch (_) {
+    fs = null;
+  }
+}
+
+module.exports = fs;
diff --git a/logtape/fs.js b/logtape/fs.js
new file mode 100644
index 0000000..1c2b978
--- /dev/null
+++ b/logtape/fs.js
@@ -0,0 +1 @@
+export * from "node:fs";
diff --git a/logtape/fs.mjs b/logtape/fs.mjs
new file mode 100644
index 0000000..3e9d1ed
--- /dev/null
+++ b/logtape/fs.mjs
@@ -0,0 +1,20 @@
+let fs = null;
+if (
+  "process" in globalThis && "versions" in globalThis.process &&
+    "node" in globalThis.process.versions &&
+    typeof globalThis.caches === "undefined" &&
+    typeof globalThis.addEventListener !== "function" ||
+  "Bun" in globalThis
+) {
+  try {
+    fs = await import("node" + ":fs");
+  } catch (e) {
+    if (e instanceof TypeError) {
+      fs = null;
+    } else {
+      throw e;
+    }
+  }
+}
+
+export default fs;
diff --git a/logtape/fs.ts b/logtape/fs.ts
new file mode 100644
index 0000000..29de881
--- /dev/null
+++ b/logtape/fs.ts
@@ -0,0 +1,22 @@
+let fs = null;
+if (
+  // @ts-ignore: process is a global variable
+  "process" in globalThis && "versions" in globalThis.process &&
+    // @ts-ignore: process is a global variable
+    "node" in globalThis.process.versions &&
+    typeof globalThis.caches === "undefined" &&
+    typeof globalThis.addEventListener !== "function" ||
+  "Bun" in globalThis
+) {
+  try {
+    fs = await import("node" + ":fs");
+  } catch (e) {
+    if (e instanceof TypeError) {
+      fs = null;
+    } else {
+      throw e;
+    }
+  }
+}
+
+export default fs;