diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..50d08d0
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+npm
\ No newline at end of file
diff --git a/build_npm.ts b/build_npm.ts
new file mode 100644
index 0000000..4ec655b
--- /dev/null
+++ b/build_npm.ts
@@ -0,0 +1,70 @@
+import { build, emptyDir } from "https://deno.land/x/dnt@0.40.0/mod.ts";
+
+const version = Deno.args[0];
+
+if (!version) {
+  throw new Error("Please specify a version.");
+}
+
+await emptyDir("./npm");
+
+await build({
+  entryPoints: ["./mod.ts"], // Replace with your actual entry point
+  outDir: "./npm",
+  testPattern: "**/*(*.test|integration).{ts,tsx,js,mjs,jsx}",
+  shims: {
+    deno: {
+      test: "dev",
+    },
+  },
+  compilerOptions: {
+    lib: ["ESNext", "DOM"],
+  },
+  mappings: {
+    "node:stream/web": {
+      name: "node:stream/web",
+    },
+  },
+  package: {
+    name: "s3-lite-client",
+    version: version,
+    description: "This is a lightweight S3 client for Node.js and Deno.",
+    license: "MIT",
+    repository: {
+      type: "git",
+      url: "git+https://github.com/bradenmacdonald/deno-s3-lite-client.git",
+    },
+    bugs: {
+      url: "https://github.com/bradenmacdonald/deno-s3-lite-client/issues",
+    },
+    engines: {
+      "node": ">=20",
+    },
+    author: {
+      "name": "Braden MacDonald",
+      "url": "https://github.com/bradenmacdonald",
+    },
+    contributors: [
+      "Martin Donadieu <martindonadieu@gmail.com> (https://martin.solos.ventures/)",
+    ],
+    devDependencies: {
+      "@types/node": "^20.11.1",
+    },
+    keywords: [
+      "api",
+      "lite",
+      "amazon",
+      "minio",
+      "cloud",
+      "s3",
+      "storage",
+    ],
+  },
+  postBuild() {
+    // Copy additional files to the npm directory if needed
+    Deno.copyFileSync("LICENSE", "npm/LICENSE");
+    Deno.copyFileSync("README.md", "npm/README.md");
+  },
+});
+
+console.log("Build complete. Run `cd npm && npm publish && cd ..`.");
diff --git a/client.ts b/client.ts
index 8f50b34..426beff 100644
--- a/client.ts
+++ b/client.ts
@@ -648,10 +648,20 @@ export class Client {
     if (typeof streamOrData === "string") {
       // Convert to binary using UTF-8
       const binaryData = new TextEncoder().encode(streamOrData);
-      stream = ReadableStream.from([binaryData]);
+      stream = new ReadableStream({
+        start(controller) {
+          controller.enqueue(binaryData);
+          controller.close();
+        },
+      });
       size = binaryData.length;
     } else if (streamOrData instanceof Uint8Array) {
-      stream = ReadableStream.from([streamOrData]);
+      stream = new ReadableStream({
+        start(controller) {
+          controller.enqueue(streamOrData);
+          controller.close();
+        },
+      });
       size = streamOrData.byteLength;
     } else if (streamOrData instanceof ReadableStream) {
       stream = streamOrData;
diff --git a/deno.jsonc b/deno.jsonc
index ba454f4..693c37c 100644
--- a/deno.jsonc
+++ b/deno.jsonc
@@ -1,6 +1,15 @@
 {
   "fmt": {
-    "lineWidth": 120
+    "lineWidth": 120,
+    "exclude": ["npm/"]
   },
-  "lock": false
+  "lint": {
+    "exclude": ["npm/"]
+  },
+  "lock": false,
+  "tasks": {
+    "test-integration": "deno test --allow-net integration.ts",
+    "npm-build": "deno run -A --no-check build_npm.ts",
+    "npm-publish": "cd npm && npm publish && cd .."
+  }
 }
diff --git a/integration.ts b/integration.ts
index 63eb0e9..714f35f 100644
--- a/integration.ts
+++ b/integration.ts
@@ -91,11 +91,14 @@ Deno.test({
   name: "putObject() can stream a large file upload",
   fn: async () => {
     // First generate a 32MiB file in memory, 1 MiB at a time, as a stream
-    const dataStream = ReadableStream.from(async function* () {
-      for (let i = 0; i < 32; i++) {
-        yield new Uint8Array(1024 * 1024).fill(i % 256); // Yield 1MB of data
-      }
-    }());
+    const dataStream = new ReadableStream({
+      start(controller) {
+        for (let i = 0; i < 32; i++) {
+          controller.enqueue(new Uint8Array(1024 * 1024).fill(i % 256)); // Yield 1MB of data
+        }
+        controller.close();
+      },
+    });
 
     // Upload the 32MB stream data as 7 5MB parts. The client doesn't know in advance how big the stream is.
     const key = "test-32m.dat";
diff --git a/mod.ts b/mod.ts
index 4f8deca..0973cb8 100644
--- a/mod.ts
+++ b/mod.ts
@@ -1,2 +1,4 @@
+import "./node_shims.ts";
+
 export { Client as S3Client } from "./client.ts";
 export * as S3Errors from "./errors.ts";
diff --git a/node_shims.ts b/node_shims.ts
new file mode 100644
index 0000000..a2b35d8
--- /dev/null
+++ b/node_shims.ts
@@ -0,0 +1,25 @@
+if (!("ReadableStream" in globalThis) || !("TransformStream" in globalThis) || !("WritableStream" in globalThis)) {
+  (async () => {
+    const { ReadableStream, TransformStream, WritableStream } = await import("node:stream/web");
+    Object.defineProperties(globalThis, {
+      "ReadableStream": {
+        value: ReadableStream,
+        writable: true,
+        enumerable: false,
+        configurable: true,
+      },
+      "TransformStream": {
+        value: TransformStream,
+        writable: true,
+        enumerable: false,
+        configurable: true,
+      },
+      "WritableStream": {
+        value: WritableStream,
+        writable: true,
+        enumerable: false,
+        configurable: true,
+      },
+    });
+  })();
+}
diff --git a/signing.ts b/signing.ts
index cc58695..ca76c90 100644
--- a/signing.ts
+++ b/signing.ts
@@ -153,13 +153,12 @@ function getHeadersToSign(headers: Headers): string[] {
     "content-type",
     "user-agent",
   ];
-  const headersToSign = [];
-  for (const key of headers.keys()) {
-    if (ignoredHeaders.includes(key.toLowerCase())) {
-      continue; // Ignore this header
+  const headersToSign: string[] = [];
+  headers.forEach((_value, key) => {
+    if (!ignoredHeaders.includes(key.toLowerCase())) {
+      headersToSign.push(key);
     }
-    headersToSign.push(key);
-  }
+  });
   headersToSign.sort();
   return headersToSign;
 }
diff --git a/transform-chunk-sizes.test.ts b/transform-chunk-sizes.test.ts
index 935db31..b55e1bf 100644
--- a/transform-chunk-sizes.test.ts
+++ b/transform-chunk-sizes.test.ts
@@ -9,7 +9,7 @@ import { TransformChunkSizes } from "./transform-chunk-sizes.ts";
  */
 class NumberSource extends ReadableStream<Uint8Array> {
   constructor(delayMs: number, chunksCount: number, bytesPerChunk = 1) {
-    let intervalTimer: number;
+    let intervalTimer: ReturnType<typeof setTimeout>;
     let i = 0;
     super({
       start(controller) {