diff --git a/src/fsa-to-node/FsaNodeFs.ts b/src/fsa-to-node/FsaNodeFs.ts
index eeb258e43..ced5acf27 100644
--- a/src/fsa-to-node/FsaNodeFs.ts
+++ b/src/fsa-to-node/FsaNodeFs.ts
@@ -829,7 +829,7 @@ export class FsaNodeFs implements FsCallbackApi, FsSynchronousApi, FsCommonObjec
       : ({ encoding: options } as opts.IWriteStreamOptions);
     const filename = pathToFilename(path);
     const location = pathToLocation(filename);
-    const flags = flagsToNumber(optionsObj.flags);
+    const flags = flagsToNumber(optionsObj.flags ?? 'w');
     const createIfMissing = !!(flags & FLAG.O_CREAT);
     const handle = this.getFile(location[0], location[1], 'createWriteStream', createIfMissing);
     return new FsaNodeWriteStream(handle, filename, optionsObj);
diff --git a/src/fsa-to-node/FsaNodeWriteStream.ts b/src/fsa-to-node/FsaNodeWriteStream.ts
index 3a28e3fcc..f3fb027b0 100644
--- a/src/fsa-to-node/FsaNodeWriteStream.ts
+++ b/src/fsa-to-node/FsaNodeWriteStream.ts
@@ -1,6 +1,7 @@
 import { Writable } from 'stream';
 import { Defer } from 'thingies/es6/Defer';
-import type { IFileSystemFileHandle } from '../fsa/types';
+import { codeMutex } from 'thingies/es6/codeMutex';
+import type { IFileSystemFileHandle, IFileSystemWritableFileStream } from '../fsa/types';
 import type { IWriteStream } from '../node/types/misc';
 import type { IWriteStreamOptions } from '../node/types/options';
 
@@ -21,24 +22,27 @@ import type { IWriteStreamOptions } from '../node/types/options';
  * swap file), but that is the trade-off we have to make.
  */
 export class FsaNodeWriteStream extends Writable implements IWriteStream {
-  protected __pending: boolean = true;
-  protected ready = new Defer<void>();
-  protected closed: boolean = false;
+  protected __pending__: boolean = true;
+  protected __stream__: Promise<IFileSystemWritableFileStream>;
+  protected __closed__: boolean = false;
+  protected readonly __mutex__ = codeMutex();
 
   public constructor(
-    protected readonly handle: Promise<IFileSystemFileHandle>,
+    handle: Promise<IFileSystemFileHandle>,
     public readonly path: string,
     protected readonly options?: IWriteStreamOptions,
   ) {
     super();
-    handle
-      .then(() => {
-        this.__pending = false;
-        this.ready.resolve();
-      })
-      .catch(error => {
-        this.ready.reject(error);
-      });
+    const stream = new Defer<IFileSystemWritableFileStream>();
+    this.__stream__ = stream.promise;
+    (async () => {
+      const fsaHandle = await handle;
+      const writable = await fsaHandle.createWritable({keepExistingData: true});
+      this.__pending__ = false;
+      stream.resolve(writable);
+    })().catch(error => {
+      stream.reject(error);
+    });
   }
 
   // ------------------------------------------------------------- IWriteStream
@@ -48,16 +52,82 @@ export class FsaNodeWriteStream extends Writable implements IWriteStream {
   }
 
   public get pending(): boolean {
-    return this.__pending;
+    return this.__pending__;
   }
 
-  public close(): void {}
+  public close(cb): void {
+    if (cb) this.once('close', cb);
+    if (this.__closed__) {
+      process.nextTick(() => this.emit('close'));
+      return;
+    }
+    this.__closed__ = true;
+    (async () => {
+      try {
+        const writable = await this.__stream__;
+        this.__mutex__(async () => {
+          console.log('closing')
+          await writable.close();
+        });
+        this.emit('close');
+      } catch (error) {
+        this.emit('error', error);
+        this.emit('close', error);
+      }
+    })().catch(() => {});
+  }
 
   // ----------------------------------------------------------------- Writable
 
-  _write(chunk: any, encoding: string, callback: (error?: Error | null) => void): void {}
+  private async ___write___(buffers: Buffer[]): Promise<void> {
+    const writable = await this.__stream__;
+    this.__mutex__(async () => {
+      for (const buffer of buffers) {
+        try {
+          console.log(1);
+          await writable.write(buffer);
+          console.log(2);
+        } catch (error) {
+         console.log('err', error);
+        }
+      }
+    });
+  }
+
+  _write(chunk: any, encoding: string, callback: (error?: Error | null) => void): void {
+    (async () => {
+      try {
+        await this.___write___([chunk]);
+        callback(null);
+      } catch (error) {
+        callback(error);
+      }
+    })().catch(() => {});
+  }
 
-  _writev(chunks: Array<{ chunk: any; encoding: string }>, callback: (error?: Error | null) => void): void {}
+  _writev(chunks: Array<{ chunk: any; encoding: string }>, callback: (error?: Error | null) => void): void {
+    (async () => {
+      try {
+        const buffers = chunks.map(({chunk}) => chunk);
+        await this.___write___(buffers);
+        callback(null);
+      } catch (error) {
+        callback(error);
+      }
+    })().catch(() => {});
+  }
 
-  _final(callback: (error?: Error | null) => void): void {}
+  _final(callback: (error?: Error | null) => void): void {
+    (async () => {
+      try {
+        const writable = await this.__stream__;
+        this.__mutex__(async () => {
+          await writable.close();
+        });
+        callback(null);
+      } catch (error) {
+        callback(error);
+      }
+    })().catch(() => {});
+  }
 }
diff --git a/src/fsa-to-node/__tests__/FsaNodeFs.test.ts b/src/fsa-to-node/__tests__/FsaNodeFs.test.ts
index 971b357d2..9604f2c6a 100644
--- a/src/fsa-to-node/__tests__/FsaNodeFs.test.ts
+++ b/src/fsa-to-node/__tests__/FsaNodeFs.test.ts
@@ -631,3 +631,17 @@ describe('.read()', () => {
     expect(buffer[1]).toBe(115);
   });
 });
+
+describe('.createWriteStream()', () => {
+  test.only('can use stream to write to a file', async () => {
+    const { fs, mfs } = setup({ folder: { file: 'test' }, 'empty-folder': null, 'f.html': 'test' });
+    const stream = fs.createWriteStream('/folder/file');
+    stream.write('a');
+    const onClose = new Promise(resolve => stream.on('close', (err) => {
+      resolve(err);
+    }));
+    stream.close();
+    await onClose;
+    console.log(mfs.__vol.toJSON());
+  });
+});
diff --git a/src/node-to-fsa/NodeFileSystemWritableFileStream.ts b/src/node-to-fsa/NodeFileSystemWritableFileStream.ts
index 63f112695..04df91a24 100644
--- a/src/node-to-fsa/NodeFileSystemWritableFileStream.ts
+++ b/src/node-to-fsa/NodeFileSystemWritableFileStream.ts
@@ -120,10 +120,15 @@ export class NodeFileSystemWritableFileStream extends WritableStream implements
   }
 
   protected async writeBase(chunk: Data): Promise<void> {
+    console.log('base')
     const writer = this.getWriter();
+    console.log('writer')
     try {
-      await writer.write(chunk);
+      console.log('write', chunk)
+      await writer.write(new Uint8Array([123]));
+      console.log('done')
     } finally {
+      console.log('finally');
       writer.releaseLock();
     }
   }
@@ -147,7 +152,11 @@ export class NodeFileSystemWritableFileStream extends WritableStream implements
           case DataView:
             return this.writeBase(params);
           default: {
-            if (ArrayBuffer.isView(params)) return this.writeBase(params);
+            if (ArrayBuffer.isView(params)) {
+
+              console.log('ERIT', params)
+              return this.writeBase(params);
+            }
             else {
               const options = params as FileSystemWritableFileStreamParams;
               switch (options.type) {
diff --git a/src/node/types/misc.ts b/src/node/types/misc.ts
index 5d7a6c56e..4ee3f1e64 100644
--- a/src/node/types/misc.ts
+++ b/src/node/types/misc.ts
@@ -94,7 +94,7 @@ export interface IWriteStream extends Writable {
   bytesWritten: number;
   path: string;
   pending: boolean;
-  close();
+  close(callback?: (err?: Error) => void): void;
 }
 
 export interface IFSWatcher extends EventEmitter {
diff --git a/tsconfig.json b/tsconfig.json
index a1cab753f..38dc1a6be 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -11,5 +11,14 @@
     "declaration": true
   },
   "include": ["src"],
-  "exclude": ["src/__tests__"]
+  "exclude": [
+    "src/__tests__",
+    "node_modules",
+    "lib",
+    "es6",
+    "es2020",
+    "esm",
+    "docs",
+    "README.md"
+  ]
 }