From 329b98f67bca609387dd9070074dec3adc8a0a8c Mon Sep 17 00:00:00 2001
From: PickBas <sayed.kirill@gmail.com>
Date: Thu, 11 Jun 2026 15:50:15 +0200
Subject: [PATCH 1/2] fs: add windowsHandle option to file streams

Fixes: https://github.com/nodejs/node/issues/57288
Signed-off-by: PickBas <sayed.kirill@gmail.com>
---
 doc/api/fs.md                                 | 22 +++++++
 lib/internal/fs/streams.js                    | 35 +++++++++-
 src/node_file.cc                              | 29 +++++++++
 test/addons/fs-windows-handle/binding.cc      | 64 +++++++++++++++++++
 test/addons/fs-windows-handle/binding.gyp     |  9 +++
 test/addons/fs-windows-handle/test.js         | 35 ++++++++++
 .../parallel/test-fs-stream-windows-handle.js | 42 ++++++++++++
 7 files changed, 234 insertions(+), 2 deletions(-)
 create mode 100644 test/addons/fs-windows-handle/binding.cc
 create mode 100644 test/addons/fs-windows-handle/binding.gyp
 create mode 100644 test/addons/fs-windows-handle/test.js
 create mode 100644 test/parallel/test-fs-stream-windows-handle.js

diff --git a/doc/api/fs.md b/doc/api/fs.md
index b02c337a6abe..420e501a493a 100644
--- a/doc/api/fs.md
+++ b/doc/api/fs.md
@@ -2944,6 +2944,9 @@ behavior is similar to `cp dir1/ dir2/`.
 <!-- YAML
 added: v0.1.31
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/63851
+    description: Add the `windowsHandle` option.
   - version: v16.10.0
     pr-url: https://github.com/nodejs/node/pull/40013
     description: The `fs` option does not need `open` method if an `fd` was provided.
@@ -3000,6 +3003,8 @@ changes:
   * `highWaterMark` {integer} **Default:** `64 * 1024`
   * `fs` {Object|null} **Default:** `null`
   * `signal` {AbortSignal|null} **Default:** `null`
+  * `windowsHandle` {integer} A raw Win32 `HANDLE` value to read from, in place
+    of `fd`. Windows only. **Default:** `null`
 * Returns: {fs.ReadStream}
 
 `options` can include `start` and `end` values to read a range of bytes from
@@ -3020,6 +3025,12 @@ If `fd` points to a character device that only supports blocking reads
 available. This can prevent the process from exiting and the stream from
 closing naturally.
 
+On Windows, a value passed in `fd` is interpreted as a CRT file descriptor. To
+use a raw Win32 `HANDLE` instead, such as an inherited anonymous pipe handle
+obtained from another process, pass it as `windowsHandle`. The handle is wrapped
+in a file descriptor that the stream owns and closes. The `windowsHandle` option
+throws on non-Windows platforms and cannot be combined with the `fs` option.
+
 By default, the stream will emit a `'close'` event after it has been
 destroyed.  Set the `emitClose` option to `false` to change this behavior.
 
@@ -3070,6 +3081,9 @@ If `options` is a string, then it specifies the encoding.
 <!-- YAML
 added: v0.1.31
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/63851
+    description: Add the `windowsHandle` option.
   - version: v22.0.0
     pr-url: https://github.com/nodejs/node/pull/52037
     description: bump default highWaterMark.
@@ -3134,6 +3148,8 @@ changes:
     [`stream.getDefaultHighWaterMark()`][].
   * `flush` {boolean} If `true`, the underlying file descriptor is flushed
     prior to closing it. **Default:** `false`.
+  * `windowsHandle` {integer} A raw Win32 `HANDLE` value to write to, in place
+    of `fd`. Windows only. **Default:** `null`
 * Returns: {fs.WriteStream}
 
 `options` may also include a `start` option to allow writing data at some
@@ -3148,6 +3164,12 @@ then the file descriptor won't be closed, even if there's an error.
 It is the application's responsibility to close it and make sure there's no
 file descriptor leak.
 
+On Windows, a value passed in `fd` is interpreted as a CRT file descriptor. To
+use a raw Win32 `HANDLE` instead, such as an inherited anonymous pipe handle
+obtained from another process, pass it as `windowsHandle`. The handle is wrapped
+in a file descriptor that the stream owns and closes. The `windowsHandle` option
+throws on non-Windows platforms and cannot be combined with the `fs` option.
+
 By default, the stream will emit a `'close'` event after it has been
 destroyed.  Set the `emitClose` option to `false` to change this behavior.
 
diff --git a/lib/internal/fs/streams.js b/lib/internal/fs/streams.js
index c2e8abc4efda..ac7784d642d0 100644
--- a/lib/internal/fs/streams.js
+++ b/lib/internal/fs/streams.js
@@ -13,8 +13,11 @@ const {
 } = primordials;
 
 const {
+  ERR_FEATURE_UNAVAILABLE_ON_PLATFORM,
+  ERR_INCOMPATIBLE_OPTION_PAIR,
   ERR_INVALID_ARG_TYPE,
   ERR_METHOD_NOT_IMPLEMENTED,
+  ERR_MISSING_OPTION,
   ERR_OUT_OF_RANGE,
   ERR_STREAM_DESTROYED,
   ERR_SYSTEM_ERROR,
@@ -40,6 +43,9 @@ const {
 } = require('internal/fs/utils');
 const { Readable, Writable, finished } = require('stream');
 const { toPathIfFileURL } = require('internal/url');
+const { isWindows } = require('internal/util');
+const binding = internalBinding('fs');
+const { O_RDONLY, O_WRONLY } = internalBinding('constants').fs;
 const kIoDone = Symbol('kIoDone');
 const kIsPerformingIO = Symbol('kIsPerformingIO');
 
@@ -160,6 +166,23 @@ function importFd(stream, options) {
                                  ['number', 'FileHandle'], options.fd);
 }
 
+function importWindowsHandle(stream, options, flags) {
+  if (options.windowsHandle == null) {
+    throw new ERR_MISSING_OPTION('options.windowsHandle');
+  }
+  if (!isWindows) {
+    throw new ERR_FEATURE_UNAVAILABLE_ON_PLATFORM('windowsHandle');
+  }
+  if (options.fs) {
+    // The HANDLE is wrapped using the real filesystem, so a custom fs
+    // implementation cannot be combined with it.
+    throw new ERR_METHOD_NOT_IMPLEMENTED('windowsHandle with fs');
+  }
+  validateInteger(options.windowsHandle, 'options.windowsHandle');
+  stream[kFs] = fs;
+  return binding.handleToFd(options.windowsHandle, flags);
+}
+
 function ReadStream(path, options) {
   if (!(this instanceof ReadStream))
     return new ReadStream(path, options);
@@ -173,7 +196,11 @@ function ReadStream(path, options) {
     options.autoDestroy = false;
   }
 
-  if (options.fd == null) {
+  if (options.fd != null && options.windowsHandle != null) {
+    throw new ERR_INCOMPATIBLE_OPTION_PAIR('windowsHandle', 'fd');
+  } else if (options.windowsHandle != null) {
+    this.fd = getValidatedFd(importWindowsHandle(this, options, O_RDONLY));
+  } else if (options.fd == null) {
     this.fd = null;
     this[kFs] = options.fs || fs;
     validateFunction(this[kFs].open, 'options.fs.open');
@@ -325,7 +352,11 @@ function WriteStream(path, options) {
   // Only buffers are supported.
   options.decodeStrings = true;
 
-  if (options.fd == null) {
+  if (options.fd != null && options.windowsHandle != null) {
+    throw new ERR_INCOMPATIBLE_OPTION_PAIR('windowsHandle', 'fd');
+  } else if (options.windowsHandle != null) {
+    this.fd = getValidatedFd(importWindowsHandle(this, options, O_WRONLY));
+  } else if (options.fd == null) {
     this.fd = null;
     this[kFs] = options.fs || fs;
     validateFunction(this[kFs].open, 'options.fs.open');
diff --git a/src/node_file.cc b/src/node_file.cc
index 78bb84b9f06c..72bdf1338929 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -4150,6 +4150,28 @@ InternalFieldInfoBase* BindingData::Serialize(int index) {
   return info;
 }
 
+#ifdef _WIN32
+static void HandleToFd(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+  CHECK_GE(args.Length(), 1);
+  CHECK(args[0]->IsNumber());
+
+  int flags = 0;
+  if (args[1]->IsNumber()) {
+    flags = args[1].As<Int32>()->Value();
+  }
+
+  intptr_t value =
+      static_cast<intptr_t>(args[0].As<Number>()->Value());
+
+  int fd = _open_osfhandle(value, flags);
+  if (fd == -1) {
+    return env->ThrowErrnoException(errno, "_open_osfhandle");
+  }
+  args.GetReturnValue().Set(fd);
+}
+#endif  // _WIN32
+
 void BindingData::CreatePerIsolateProperties(IsolateData* isolate_data,
                                              Local<ObjectTemplate> target) {
   Isolate* isolate = isolate_data->isolate();
@@ -4216,6 +4238,10 @@ static void CreatePerIsolateProperties(IsolateData* isolate_data,
 
   SetMethod(isolate, target, "mkdtemp", Mkdtemp);
 
+#ifdef _WIN32
+  SetMethod(isolate, target, "handleToFd", HandleToFd);
+#endif
+
   SetMethod(isolate, target, "cpSyncCheckPaths", CpSyncCheckPaths);
   SetMethod(isolate, target, "cpSyncOverrideFile", CpSyncOverrideFile);
   SetMethod(isolate, target, "cpSyncCopyDir", CpSyncCopyDir);
@@ -4343,6 +4369,9 @@ void RegisterExternalReferences(ExternalReferenceRegistry* registry) {
   registry->Register(LUTimes);
 
   registry->Register(Mkdtemp);
+#ifdef _WIN32
+  registry->Register(HandleToFd);
+#endif
   registry->Register(NewFSReqCallback);
 
   registry->Register(FileHandle::New);
diff --git a/test/addons/fs-windows-handle/binding.cc b/test/addons/fs-windows-handle/binding.cc
new file mode 100644
index 000000000000..06aaf924ab0a
--- /dev/null
+++ b/test/addons/fs-windows-handle/binding.cc
@@ -0,0 +1,64 @@
+#include <node.h>
+#include <v8.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+namespace {
+
+using v8::Context;
+using v8::FunctionCallbackInfo;
+using v8::Isolate;
+using v8::Local;
+using v8::Number;
+using v8::Object;
+using v8::String;
+using v8::Value;
+
+// Creates an anonymous pipe and returns its raw Win32 read/write HANDLE values
+// as JS numbers. These are NOT CRT file descriptors, so passing them as the
+// `windowsHandle` stream option exercises the HANDLE -> fd conversion path on
+// Windows. Returns undefined on other platforms.
+void CreatePipeHandles(const FunctionCallbackInfo<Value>& args) {
+  Isolate* isolate = args.GetIsolate();
+#ifdef _WIN32
+  Local<Context> context = isolate->GetCurrentContext();
+
+  HANDLE read_handle = nullptr;
+  HANDLE write_handle = nullptr;
+  if (!CreatePipe(&read_handle, &write_handle, nullptr, 0)) {
+    isolate->ThrowException(v8::Exception::Error(
+        String::NewFromUtf8(isolate, "CreatePipe failed").ToLocalChecked()));
+    return;
+  }
+
+  Local<Object> result = Object::New(isolate);
+  result
+      ->Set(context,
+            String::NewFromUtf8(isolate, "readHandle").ToLocalChecked(),
+            Number::New(isolate,
+                        static_cast<double>(
+                            reinterpret_cast<intptr_t>(read_handle))))
+      .Check();
+  result
+      ->Set(context,
+            String::NewFromUtf8(isolate, "writeHandle").ToLocalChecked(),
+            Number::New(isolate,
+                        static_cast<double>(
+                            reinterpret_cast<intptr_t>(write_handle))))
+      .Check();
+  args.GetReturnValue().Set(result);
+#else
+  args.GetReturnValue().SetUndefined();
+#endif
+}
+
+}  // anonymous namespace
+
+extern "C" NODE_MODULE_EXPORT void
+NODE_MODULE_INITIALIZER(Local<Object> exports,
+                        Local<Value> module,
+                        Local<Context> context) {
+  NODE_SET_METHOD(exports, "createPipeHandles", CreatePipeHandles);
+}
diff --git a/test/addons/fs-windows-handle/binding.gyp b/test/addons/fs-windows-handle/binding.gyp
new file mode 100644
index 000000000000..7e0f38c27d57
--- /dev/null
+++ b/test/addons/fs-windows-handle/binding.gyp
@@ -0,0 +1,9 @@
+{
+  'targets': [
+    {
+      'target_name': 'binding',
+      'sources': [ 'binding.cc' ],
+      'includes': ['../common.gypi'],
+    },
+  ]
+}
diff --git a/test/addons/fs-windows-handle/test.js b/test/addons/fs-windows-handle/test.js
new file mode 100644
index 000000000000..a3a33d062455
--- /dev/null
+++ b/test/addons/fs-windows-handle/test.js
@@ -0,0 +1,35 @@
+'use strict';
+// Verifies that fs.createReadStream()/createWriteStream() accept a raw Win32
+// HANDLE through the `windowsHandle` option, as happens when a parent process
+// passes an inherited anonymous pipe handle. The addon produces such handles
+// via CreatePipe(); Node must wrap them in CRT file descriptors instead of
+// failing with EBADF.
+
+const common = require('../../common');
+
+if (!common.isWindows) {
+  common.skip('windowsHandle is Windows-only');
+}
+
+const assert = require('assert');
+const fs = require('fs');
+
+const binding = require(`./build/${common.buildType}/binding`);
+
+const { readHandle, writeHandle } = binding.createPipeHandles();
+assert.strictEqual(typeof readHandle, 'number');
+assert.strictEqual(typeof writeHandle, 'number');
+
+const payload = 'payload';
+
+const chunks = [];
+const rs = fs.createReadStream(null, { windowsHandle: readHandle });
+rs.on('error', (err) => assert.fail(err));
+rs.on('data', (chunk) => chunks.push(chunk));
+rs.on('end', common.mustCall(() => {
+  assert.strictEqual(Buffer.concat(chunks).toString(), payload);
+}));
+
+const ws = fs.createWriteStream(null, { windowsHandle: writeHandle });
+ws.on('error', (err) => assert.fail(err));
+ws.end(payload);
diff --git a/test/parallel/test-fs-stream-windows-handle.js b/test/parallel/test-fs-stream-windows-handle.js
new file mode 100644
index 000000000000..15232932135f
--- /dev/null
+++ b/test/parallel/test-fs-stream-windows-handle.js
@@ -0,0 +1,42 @@
+'use strict';
+
+// Tests option validation for the `windowsHandle` option of
+// fs.createReadStream()/createWriteStream(). The functional round-trip on
+// Windows (where a real Win32 HANDLE is wrapped in a file descriptor) is
+// covered by test/addons/fs-windows-handle.
+
+const common = require('../common');
+const assert = require('assert');
+const fs = require('fs');
+
+const handle = 1;
+
+for (const create of [fs.createReadStream, fs.createWriteStream]) {
+  assert.throws(() => create(null, { windowsHandle: handle, fd: 2 }), {
+    code: 'ERR_INCOMPATIBLE_OPTION_PAIR',
+  });
+}
+
+if (!common.isWindows) {
+  for (const create of [fs.createReadStream, fs.createWriteStream]) {
+    assert.throws(() => create(null, { windowsHandle: handle }), {
+      code: 'ERR_FEATURE_UNAVAILABLE_ON_PLATFORM',
+    });
+  }
+  return;
+}
+
+for (const create of [fs.createReadStream, fs.createWriteStream]) {
+  // Cannot be combined with a custom `fs` implementation.
+  assert.throws(() => create(null, { windowsHandle: handle, fs: {} }), {
+    code: 'ERR_METHOD_NOT_IMPLEMENTED',
+  });
+
+  // Must be an integer.
+  assert.throws(() => create(null, { windowsHandle: 'nope' }), {
+    code: 'ERR_INVALID_ARG_TYPE',
+  });
+  assert.throws(() => create(null, { windowsHandle: 1.5 }), {
+    code: 'ERR_OUT_OF_RANGE',
+  });
+}

From 36f2bcd93636d44469f162e08e2eb7b6fd9611e7 Mon Sep 17 00:00:00 2001
From: PickBas <sayed.kirill@gmail.com>
Date: Fri, 12 Jun 2026 09:48:09 +0200
Subject: [PATCH 2/2] fs: use bigint for windowsHandle option

Signed-off-by: PickBas <sayed.kirill@gmail.com>
---
 doc/api/fs.md                                 |  4 ++--
 lib/internal/fs/streams.js                    |  7 ++++--
 src/node_file.cc                              | 11 +++++++---
 test/addons/fs-windows-handle/binding.cc      | 22 +++++++++----------
 test/addons/fs-windows-handle/test.js         |  4 ++--
 .../parallel/test-fs-stream-windows-handle.js | 11 +++++++---
 6 files changed, 35 insertions(+), 24 deletions(-)

diff --git a/doc/api/fs.md b/doc/api/fs.md
index 420e501a493a..d742cbb2145e 100644
--- a/doc/api/fs.md
+++ b/doc/api/fs.md
@@ -3003,7 +3003,7 @@ changes:
   * `highWaterMark` {integer} **Default:** `64 * 1024`
   * `fs` {Object|null} **Default:** `null`
   * `signal` {AbortSignal|null} **Default:** `null`
-  * `windowsHandle` {integer} A raw Win32 `HANDLE` value to read from, in place
+  * `windowsHandle` {bigint} A raw Win32 `HANDLE` value to read from, in place
     of `fd`. Windows only. **Default:** `null`
 * Returns: {fs.ReadStream}
 
@@ -3148,7 +3148,7 @@ changes:
     [`stream.getDefaultHighWaterMark()`][].
   * `flush` {boolean} If `true`, the underlying file descriptor is flushed
     prior to closing it. **Default:** `false`.
-  * `windowsHandle` {integer} A raw Win32 `HANDLE` value to write to, in place
+  * `windowsHandle` {bigint} A raw Win32 `HANDLE` value to write to, in place
     of `fd`. Windows only. **Default:** `null`
 * Returns: {fs.WriteStream}
 
diff --git a/lib/internal/fs/streams.js b/lib/internal/fs/streams.js
index ac7784d642d0..4c53f7ea23e1 100644
--- a/lib/internal/fs/streams.js
+++ b/lib/internal/fs/streams.js
@@ -23,6 +23,7 @@ const {
   ERR_SYSTEM_ERROR,
 } = require('internal/errors').codes;
 const {
+  isWindows,
   kEmptyObject,
 } = require('internal/util');
 const {
@@ -43,7 +44,6 @@ const {
 } = require('internal/fs/utils');
 const { Readable, Writable, finished } = require('stream');
 const { toPathIfFileURL } = require('internal/url');
-const { isWindows } = require('internal/util');
 const binding = internalBinding('fs');
 const { O_RDONLY, O_WRONLY } = internalBinding('constants').fs;
 const kIoDone = Symbol('kIoDone');
@@ -178,7 +178,10 @@ function importWindowsHandle(stream, options, flags) {
     // implementation cannot be combined with it.
     throw new ERR_METHOD_NOT_IMPLEMENTED('windowsHandle with fs');
   }
-  validateInteger(options.windowsHandle, 'options.windowsHandle');
+  if (typeof options.windowsHandle !== 'bigint') {
+    throw new ERR_INVALID_ARG_TYPE('options.windowsHandle', 'bigint',
+                                   options.windowsHandle);
+  }
   stream[kFs] = fs;
   return binding.handleToFd(options.windowsHandle, flags);
 }
diff --git a/src/node_file.cc b/src/node_file.cc
index 72bdf1338929..ae0d9f34f8e1 100644
--- a/src/node_file.cc
+++ b/src/node_file.cc
@@ -4154,15 +4154,20 @@ InternalFieldInfoBase* BindingData::Serialize(int index) {
 static void HandleToFd(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
   CHECK_GE(args.Length(), 1);
-  CHECK(args[0]->IsNumber());
+  CHECK(args[0]->IsBigInt());
 
   int flags = 0;
   if (args[1]->IsNumber()) {
     flags = args[1].As<Int32>()->Value();
   }
 
-  intptr_t value =
-      static_cast<intptr_t>(args[0].As<Number>()->Value());
+  bool lossless;
+  int64_t handle = args[0].As<BigInt>()->Int64Value(&lossless);
+  if (!lossless) {
+    return THROW_ERR_OUT_OF_RANGE(env,
+                                  "windowsHandle does not fit into 64 bits");
+  }
+  intptr_t value = static_cast<intptr_t>(handle);
 
   int fd = _open_osfhandle(value, flags);
   if (fd == -1) {
diff --git a/test/addons/fs-windows-handle/binding.cc b/test/addons/fs-windows-handle/binding.cc
index 06aaf924ab0a..72194df15e5f 100644
--- a/test/addons/fs-windows-handle/binding.cc
+++ b/test/addons/fs-windows-handle/binding.cc
@@ -7,17 +7,17 @@
 
 namespace {
 
+using v8::BigInt;
 using v8::Context;
 using v8::FunctionCallbackInfo;
 using v8::Isolate;
 using v8::Local;
-using v8::Number;
 using v8::Object;
 using v8::String;
 using v8::Value;
 
 // Creates an anonymous pipe and returns its raw Win32 read/write HANDLE values
-// as JS numbers. These are NOT CRT file descriptors, so passing them as the
+// as JS bigints. These are NOT CRT file descriptors, so passing them as the
 // `windowsHandle` stream option exercises the HANDLE -> fd conversion path on
 // Windows. Returns undefined on other platforms.
 void CreatePipeHandles(const FunctionCallbackInfo<Value>& args) {
@@ -37,16 +37,16 @@ void CreatePipeHandles(const FunctionCallbackInfo<Value>& args) {
   result
       ->Set(context,
             String::NewFromUtf8(isolate, "readHandle").ToLocalChecked(),
-            Number::New(isolate,
-                        static_cast<double>(
-                            reinterpret_cast<intptr_t>(read_handle))))
+            BigInt::New(
+                isolate,
+                static_cast<int64_t>(reinterpret_cast<intptr_t>(read_handle))))
       .Check();
   result
       ->Set(context,
             String::NewFromUtf8(isolate, "writeHandle").ToLocalChecked(),
-            Number::New(isolate,
-                        static_cast<double>(
-                            reinterpret_cast<intptr_t>(write_handle))))
+            BigInt::New(
+                isolate,
+                static_cast<int64_t>(reinterpret_cast<intptr_t>(write_handle))))
       .Check();
   args.GetReturnValue().Set(result);
 #else
@@ -56,9 +56,7 @@ void CreatePipeHandles(const FunctionCallbackInfo<Value>& args) {
 
 }  // anonymous namespace
 
-extern "C" NODE_MODULE_EXPORT void
-NODE_MODULE_INITIALIZER(Local<Object> exports,
-                        Local<Value> module,
-                        Local<Context> context) {
+extern "C" NODE_MODULE_EXPORT void NODE_MODULE_INITIALIZER(
+    Local<Object> exports, Local<Value> module, Local<Context> context) {
   NODE_SET_METHOD(exports, "createPipeHandles", CreatePipeHandles);
 }
diff --git a/test/addons/fs-windows-handle/test.js b/test/addons/fs-windows-handle/test.js
index a3a33d062455..122440ee4677 100644
--- a/test/addons/fs-windows-handle/test.js
+++ b/test/addons/fs-windows-handle/test.js
@@ -17,8 +17,8 @@ const fs = require('fs');
 const binding = require(`./build/${common.buildType}/binding`);
 
 const { readHandle, writeHandle } = binding.createPipeHandles();
-assert.strictEqual(typeof readHandle, 'number');
-assert.strictEqual(typeof writeHandle, 'number');
+assert.strictEqual(typeof readHandle, 'bigint');
+assert.strictEqual(typeof writeHandle, 'bigint');
 
 const payload = 'payload';
 
diff --git a/test/parallel/test-fs-stream-windows-handle.js b/test/parallel/test-fs-stream-windows-handle.js
index 15232932135f..299a618802cf 100644
--- a/test/parallel/test-fs-stream-windows-handle.js
+++ b/test/parallel/test-fs-stream-windows-handle.js
@@ -9,7 +9,7 @@ const common = require('../common');
 const assert = require('assert');
 const fs = require('fs');
 
-const handle = 1;
+const handle = 1n;
 
 for (const create of [fs.createReadStream, fs.createWriteStream]) {
   assert.throws(() => create(null, { windowsHandle: handle, fd: 2 }), {
@@ -32,11 +32,16 @@ for (const create of [fs.createReadStream, fs.createWriteStream]) {
     code: 'ERR_METHOD_NOT_IMPLEMENTED',
   });
 
-  // Must be an integer.
+  // Must be a bigint.
   assert.throws(() => create(null, { windowsHandle: 'nope' }), {
     code: 'ERR_INVALID_ARG_TYPE',
   });
-  assert.throws(() => create(null, { windowsHandle: 1.5 }), {
+  assert.throws(() => create(null, { windowsHandle: 1 }), {
+    code: 'ERR_INVALID_ARG_TYPE',
+  });
+
+  // Must fit into 64 bits.
+  assert.throws(() => create(null, { windowsHandle: 2n ** 64n }), {
     code: 'ERR_OUT_OF_RANGE',
   });
 }