diff --git a/.eslintrc b/.eslintrc
index e03680342..4766b9889 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -2,7 +2,7 @@
   "plugins": ["prettier"],
   "parser": "@typescript-eslint/parser",
   "extends": ["plugin:prettier/recommended", "prettier/@typescript-eslint"],
-  "ignorePatterns": ["node_modules", "coverage", "packages/pg-protocol/dist/**/*"],
+  "ignorePatterns": ["node_modules", "coverage", "packages/pg-protocol/dist/**/*", "packages/pg-query-stream/dist/**/*"],
   "parserOptions": {
     "ecmaVersion": 2017,
     "sourceType": "module"
diff --git a/package.json b/package.json
index 98e3c4e98..d87548d6d 100644
--- a/package.json
+++ b/package.json
@@ -11,7 +11,8 @@
   ],
   "scripts": {
     "test": "yarn lerna exec yarn test",
-    "build": "yarn lerna exec --scope pg-protocol yarn build",
+    "build": "tsc --build",
+    "build:watch": "tsc --build --watch",
     "pretest": "yarn build",
     "lint": "eslint '*/**/*.{js,ts,tsx}'"
   },
@@ -23,7 +24,8 @@
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-prettier": "^3.1.4",
     "lerna": "^3.19.0",
-    "prettier": "2.1.2"
+    "prettier": "2.1.2",
+    "typescript": "^4.0.3"
   },
   "prettier": {
     "semi": false,
diff --git a/packages/pg-protocol/package.json b/packages/pg-protocol/package.json
index 3ad45e4cb..7fc1eb8ac 100644
--- a/packages/pg-protocol/package.json
+++ b/packages/pg-protocol/package.json
@@ -13,7 +13,7 @@
     "chunky": "^0.0.0",
     "mocha": "^7.1.2",
     "ts-node": "^8.5.4",
-    "typescript": "^3.7.3"
+    "typescript": "^4.0.3"
   },
   "scripts": {
     "test": "mocha dist/**/*.test.js",
@@ -21,5 +21,9 @@
     "build:watch": "tsc --watch",
     "prepublish": "yarn build",
     "pretest": "yarn build"
-  }
+  },
+  "files": [
+    "/dist/*{js,ts,map}",
+    "/src"
+  ]
 }
diff --git a/packages/pg-protocol/tsconfig.json b/packages/pg-protocol/tsconfig.json
index bdbe07a39..b273c52d6 100644
--- a/packages/pg-protocol/tsconfig.json
+++ b/packages/pg-protocol/tsconfig.json
@@ -9,6 +9,7 @@
     "moduleResolution": "node",
     "sourceMap": true,
     "outDir": "dist",
+    "incremental": true,
     "baseUrl": ".",
     "declaration": true,
     "paths": {
diff --git a/packages/pg-query-stream/package.json b/packages/pg-query-stream/package.json
index 15da00837..94f9f02d0 100644
--- a/packages/pg-query-stream/package.json
+++ b/packages/pg-query-stream/package.json
@@ -2,9 +2,10 @@
   "name": "pg-query-stream",
   "version": "3.3.2",
   "description": "Postgres query result returned as readable stream",
-  "main": "index.js",
+  "main": "./dist/index.js",
+  "types": "./dist/index.d.ts",
   "scripts": {
-    "test": "mocha"
+    "test": "mocha -r ts-node/register test/**/*.ts"
   },
   "repository": {
     "type": "git",
@@ -16,12 +17,20 @@
     "query",
     "stream"
   ],
+  "files": [
+    "/dist/*{js,ts,map}",
+    "/src"
+  ],
   "author": "Brian M. Carlson",
   "license": "MIT",
   "bugs": {
     "url": "https://github.com/brianc/node-postgres/issues"
   },
   "devDependencies": {
+    "@types/node": "^14.0.0",
+    "@types/pg": "^7.14.5",
+    "@types/chai": "^4.2.13",
+    "@types/mocha": "^8.0.3",
     "JSONStream": "~0.7.1",
     "concat-stream": "~1.0.1",
     "eslint-plugin-promise": "^3.5.0",
@@ -29,7 +38,9 @@
     "pg": "^8.4.2",
     "stream-spec": "~0.3.5",
     "stream-tester": "0.0.5",
-    "through": "~2.3.4"
+    "through": "~2.3.4",
+    "ts-node": "^8.5.4",
+    "typescript": "^4.0.3"
   },
   "dependencies": {
     "pg-cursor": "^2.4.2"
diff --git a/packages/pg-query-stream/index.js b/packages/pg-query-stream/src/index.ts
similarity index 55%
rename from packages/pg-query-stream/index.js
rename to packages/pg-query-stream/src/index.ts
index 3806e60aa..c942b0441 100644
--- a/packages/pg-query-stream/index.js
+++ b/packages/pg-query-stream/src/index.ts
@@ -1,11 +1,30 @@
-const { Readable } = require('stream')
-const Cursor = require('pg-cursor')
+import { Readable } from 'stream'
+import { Submittable, Connection } from 'pg'
+import Cursor from 'pg-cursor'
 
-class PgQueryStream extends Readable {
-  constructor(text, values, config = {}) {
+interface QueryStreamConfig {
+  batchSize?: number
+  highWaterMark?: number
+  rowMode?: 'array'
+  types?: any
+}
+
+class QueryStream extends Readable implements Submittable {
+  cursor: any
+  _result: any
+
+  handleRowDescription: Function
+  handleDataRow: Function
+  handlePortalSuspended: Function
+  handleCommandComplete: Function
+  handleReadyForQuery: Function
+  handleError: Function
+  handleEmptyQuery: Function
+
+  public constructor(text: string, values?: any[], config: QueryStreamConfig = {}) {
     const { batchSize, highWaterMark = 100 } = config
-    // https://nodejs.org/api/stream.html#stream_new_stream_readable_options
-    super({ objectMode: true, emitClose: true, autoDestroy: true, highWaterMark: batchSize || highWaterMark })
+
+    super({ objectMode: true, autoDestroy: true, highWaterMark: batchSize || highWaterMark })
     this.cursor = new Cursor(text, values, config)
 
     // delegate Submittable callbacks to cursor
@@ -21,19 +40,19 @@ class PgQueryStream extends Readable {
     this._result = this.cursor._result
   }
 
-  submit(connection) {
+  public submit(connection: Connection): void {
     this.cursor.submit(connection)
   }
 
-  _destroy(_err, cb) {
-    this.cursor.close((err) => {
+  public _destroy(_err: Error, cb: Function) {
+    this.cursor.close((err?: Error) => {
       cb(err || _err)
     })
   }
 
   // https://nodejs.org/api/stream.html#stream_readable_read_size_1
-  _read(size) {
-    this.cursor.read(size, (err, rows, result) => {
+  public _read(size: number) {
+    this.cursor.read(size, (err: Error, rows: any[]) => {
       if (err) {
         // https://nodejs.org/api/stream.html#stream_errors_while_reading
         this.destroy(err)
@@ -45,4 +64,4 @@ class PgQueryStream extends Readable {
   }
 }
 
-module.exports = PgQueryStream
+export = QueryStream
diff --git a/packages/pg-query-stream/test/async-iterator.es6 b/packages/pg-query-stream/test/async-iterator.es6
deleted file mode 100644
index 47bda86d2..000000000
--- a/packages/pg-query-stream/test/async-iterator.es6
+++ /dev/null
@@ -1,112 +0,0 @@
-const QueryStream = require('../')
-const pg = require('pg')
-const assert = require('assert')
-
-const queryText = 'SELECT * FROM generate_series(0, 200) num'
-describe('Async iterator', () => {
-  it('works', async () => {
-    const stream = new QueryStream(queryText, [])
-    const client = new pg.Client()
-    await client.connect()
-    const query = client.query(stream)
-    const rows = []
-    for await (const row of query) {
-      rows.push(row)
-    }
-    assert.equal(rows.length, 201)
-    await client.end()
-  })
-
-  it('can async iterate and then do a query afterwards', async () => {
-    const stream = new QueryStream(queryText, [])
-    const client = new pg.Client()
-    await client.connect()
-    const query = client.query(stream)
-    const iteratorRows = []
-    for await (const row of query) {
-      iteratorRows.push(row)
-    }
-    assert.equal(iteratorRows.length, 201)
-    const { rows } = await client.query('SELECT NOW()')
-    assert.equal(rows.length, 1)
-    await client.end()
-  })
-
-  it('can async iterate multiple times with a pool', async () => {
-    const pool = new pg.Pool({ max: 1 })
-
-    const allRows = []
-    const run = async () => {
-      // get the client
-      const client = await pool.connect()
-      // stream some rows
-      const stream = new QueryStream(queryText, [])
-      const iteratorRows = []
-      client.query(stream)
-      for await (const row of stream) {
-        iteratorRows.push(row)
-        allRows.push(row)
-      }
-      assert.equal(iteratorRows.length, 201)
-      client.release()
-    }
-    await Promise.all([run(), run(), run()])
-    assert.equal(allRows.length, 603)
-    await pool.end()
-  })
-
-  it('can break out of iteration early', async () => {
-    const pool = new pg.Pool({ max: 1 })
-    const client = await pool.connect()
-    const rows = []
-    for await (const row of client.query(new QueryStream(queryText, [], { batchSize: 1 }))) {
-      rows.push(row)
-      break;
-    }
-    for await (const row of client.query(new QueryStream(queryText, []))) {
-      rows.push(row)
-      break;
-    }
-    for await (const row of client.query(new QueryStream(queryText, []))) {
-      rows.push(row)
-      break;
-    }
-    assert.strictEqual(rows.length, 3)
-    client.release()
-    await pool.end()
-  })
-
-  it('only returns rows on first iteration', async () => {
-    const pool = new pg.Pool({ max: 1 })
-    const client = await pool.connect()
-    const rows = []
-    const stream = client.query(new QueryStream(queryText, []))
-    for await (const row of stream) {
-      rows.push(row)
-      break;
-    }
-    for await (const row of stream) {
-      rows.push(row)
-    }
-    for await (const row of stream) {
-      rows.push(row)
-    }
-    assert.strictEqual(rows.length, 1)
-    client.release()
-    await pool.end()
-  })
-
-  it('can read with delays', async () => {
-    const pool = new pg.Pool({ max: 1 })
-    const client = await pool.connect()
-    const rows = []
-    const stream = client.query(new QueryStream(queryText, [], { batchSize: 1 }))
-    for await (const row of stream) {
-      rows.push(row)
-      await new Promise((resolve) => setTimeout(resolve, 1))
-    }
-    assert.strictEqual(rows.length, 201)
-    client.release()
-    await pool.end()
-  })
-})
diff --git a/packages/pg-query-stream/test/async-iterator.js b/packages/pg-query-stream/test/async-iterator.js
deleted file mode 100644
index 19718fe3b..000000000
--- a/packages/pg-query-stream/test/async-iterator.js
+++ /dev/null
@@ -1,4 +0,0 @@
-// only newer versions of node support async iterator
-if (!process.version.startsWith('v8')) {
-  require('./async-iterator.es6')
-}
diff --git a/packages/pg-query-stream/test/async-iterator.ts b/packages/pg-query-stream/test/async-iterator.ts
new file mode 100644
index 000000000..06539d124
--- /dev/null
+++ b/packages/pg-query-stream/test/async-iterator.ts
@@ -0,0 +1,116 @@
+import QueryStream from '../src'
+import pg from 'pg'
+import assert from 'assert'
+
+const queryText = 'SELECT * FROM generate_series(0, 200) num'
+
+// node v8 do not support async iteration
+if (!process.version.startsWith('v8')) {
+  describe('Async iterator', () => {
+    it('works', async () => {
+      const stream = new QueryStream(queryText, [])
+      const client = new pg.Client()
+      await client.connect()
+      const query = client.query(stream)
+      const rows = []
+      for await (const row of query) {
+        rows.push(row)
+      }
+      assert.equal(rows.length, 201)
+      await client.end()
+    })
+
+    it('can async iterate and then do a query afterwards', async () => {
+      const stream = new QueryStream(queryText, [])
+      const client = new pg.Client()
+      await client.connect()
+      const query = client.query(stream)
+      const iteratorRows = []
+      for await (const row of query) {
+        iteratorRows.push(row)
+      }
+      assert.equal(iteratorRows.length, 201)
+      const { rows } = await client.query('SELECT NOW()')
+      assert.equal(rows.length, 1)
+      await client.end()
+    })
+
+    it('can async iterate multiple times with a pool', async () => {
+      const pool = new pg.Pool({ max: 1 })
+
+      const allRows = []
+      const run = async () => {
+        // get the client
+        const client = await pool.connect()
+        // stream some rows
+        const stream = new QueryStream(queryText, [])
+        const iteratorRows = []
+        client.query(stream)
+        for await (const row of stream) {
+          iteratorRows.push(row)
+          allRows.push(row)
+        }
+        assert.equal(iteratorRows.length, 201)
+        client.release()
+      }
+      await Promise.all([run(), run(), run()])
+      assert.equal(allRows.length, 603)
+      await pool.end()
+    })
+
+    it('can break out of iteration early', async () => {
+      const pool = new pg.Pool({ max: 1 })
+      const client = await pool.connect()
+      const rows = []
+      for await (const row of client.query(new QueryStream(queryText, [], { batchSize: 1 }))) {
+        rows.push(row)
+        break
+      }
+      for await (const row of client.query(new QueryStream(queryText, []))) {
+        rows.push(row)
+        break
+      }
+      for await (const row of client.query(new QueryStream(queryText, []))) {
+        rows.push(row)
+        break
+      }
+      assert.strictEqual(rows.length, 3)
+      client.release()
+      await pool.end()
+    })
+
+    it('only returns rows on first iteration', async () => {
+      const pool = new pg.Pool({ max: 1 })
+      const client = await pool.connect()
+      const rows = []
+      const stream = client.query(new QueryStream(queryText, []))
+      for await (const row of stream) {
+        rows.push(row)
+        break
+      }
+      for await (const row of stream) {
+        rows.push(row)
+      }
+      for await (const row of stream) {
+        rows.push(row)
+      }
+      assert.strictEqual(rows.length, 1)
+      client.release()
+      await pool.end()
+    })
+
+    it('can read with delays', async () => {
+      const pool = new pg.Pool({ max: 1 })
+      const client = await pool.connect()
+      const rows = []
+      const stream = client.query(new QueryStream(queryText, [], { batchSize: 1 }))
+      for await (const row of stream) {
+        rows.push(row)
+        await new Promise((resolve) => setTimeout(resolve, 1))
+      }
+      assert.strictEqual(rows.length, 201)
+      client.release()
+      await pool.end()
+    })
+  })
+}
diff --git a/packages/pg-query-stream/test/client-options.js b/packages/pg-query-stream/test/client-options.ts
similarity index 62%
rename from packages/pg-query-stream/test/client-options.js
rename to packages/pg-query-stream/test/client-options.ts
index 3820d96b2..6646347fb 100644
--- a/packages/pg-query-stream/test/client-options.js
+++ b/packages/pg-query-stream/test/client-options.ts
@@ -1,17 +1,18 @@
-var pg = require('pg')
-var assert = require('assert')
-var QueryStream = require('../')
+import pg from 'pg'
+import assert from 'assert'
+import QueryStream from '../src'
 
 describe('client options', function () {
   it('uses custom types from client config', function (done) {
     const types = {
       getTypeParser: () => (string) => string,
     }
-    var client = new pg.Client({ types })
+    //@ts-expect-error
+    const client = new pg.Client({ types })
     client.connect()
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 10) num')
-    var query = client.query(stream)
-    var result = []
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 10) num')
+    const query = client.query(stream)
+    const result = []
     query.on('data', (datum) => {
       result.push(datum)
     })
diff --git a/packages/pg-query-stream/test/close.js b/packages/pg-query-stream/test/close.ts
similarity index 72%
rename from packages/pg-query-stream/test/close.js
rename to packages/pg-query-stream/test/close.ts
index 4a95464a7..97e4627d9 100644
--- a/packages/pg-query-stream/test/close.js
+++ b/packages/pg-query-stream/test/close.ts
@@ -1,16 +1,18 @@
-var assert = require('assert')
-var concat = require('concat-stream')
-
-var QueryStream = require('../')
-var helper = require('./helper')
+import assert from 'assert'
+import concat from 'concat-stream'
+import QueryStream from '../src'
+import helper from './helper'
 
 if (process.version.startsWith('v8.')) {
   console.error('warning! node less than 10lts stream closing semantics may not behave properly')
 } else {
   helper('close', function (client) {
     it('emits close', function (done) {
-      var stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [3], { batchSize: 2, highWaterMark: 2 })
-      var query = client.query(stream)
+      const stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [3], {
+        batchSize: 2,
+        highWaterMark: 2,
+      })
+      const query = client.query(stream)
       query.pipe(concat(function () {}))
       query.on('close', done)
     })
@@ -18,12 +20,12 @@ if (process.version.startsWith('v8.')) {
 
   helper('early close', function (client) {
     it('can be closed early', function (done) {
-      var stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [20000], {
+      const stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [20000], {
         batchSize: 2,
         highWaterMark: 2,
       })
-      var query = client.query(stream)
-      var readCount = 0
+      const query = client.query(stream)
+      let readCount = 0
       query.on('readable', function () {
         readCount++
         query.read()
@@ -38,7 +40,7 @@ if (process.version.startsWith('v8.')) {
     })
 
     it('can destroy stream while reading', function (done) {
-      var stream = new QueryStream('SELECT * FROM generate_series(0, 100), pg_sleep(1)')
+      const stream = new QueryStream('SELECT * FROM generate_series(0, 100), pg_sleep(1)')
       client.query(stream)
       stream.on('data', () => done(new Error('stream should not have returned rows')))
       setTimeout(() => {
@@ -48,7 +50,7 @@ if (process.version.startsWith('v8.')) {
     })
 
     it('emits an error when calling destroy with an error', function (done) {
-      var stream = new QueryStream('SELECT * FROM generate_series(0, 100), pg_sleep(1)')
+      const stream = new QueryStream('SELECT * FROM generate_series(0, 100), pg_sleep(1)')
       client.query(stream)
       stream.on('data', () => done(new Error('stream should not have returned rows')))
       setTimeout(() => {
@@ -63,7 +65,7 @@ if (process.version.startsWith('v8.')) {
     })
 
     it('can destroy stream while reading an error', function (done) {
-      var stream = new QueryStream('SELECT * from  pg_sleep(1), basdfasdf;')
+      const stream = new QueryStream('SELECT * from  pg_sleep(1), basdfasdf;')
       client.query(stream)
       stream.on('data', () => done(new Error('stream should not have returned rows')))
       stream.once('error', () => {
@@ -74,7 +76,7 @@ if (process.version.startsWith('v8.')) {
     })
 
     it('does not crash when destroying the stream immediately after calling read', function (done) {
-      var stream = new QueryStream('SELECT * from generate_series(0, 100), pg_sleep(1);')
+      const stream = new QueryStream('SELECT * from generate_series(0, 100), pg_sleep(1);')
       client.query(stream)
       stream.on('data', () => done(new Error('stream should not have returned rows')))
       stream.destroy()
@@ -82,7 +84,7 @@ if (process.version.startsWith('v8.')) {
     })
 
     it('does not crash when destroying the stream before its submitted', function (done) {
-      var stream = new QueryStream('SELECT * from generate_series(0, 100), pg_sleep(1);')
+      const stream = new QueryStream('SELECT * from generate_series(0, 100), pg_sleep(1);')
       stream.on('data', () => done(new Error('stream should not have returned rows')))
       stream.destroy()
       stream.on('close', done)
diff --git a/packages/pg-query-stream/test/concat.js b/packages/pg-query-stream/test/concat.ts
similarity index 51%
rename from packages/pg-query-stream/test/concat.js
rename to packages/pg-query-stream/test/concat.ts
index 6ce17a28e..980038578 100644
--- a/packages/pg-query-stream/test/concat.js
+++ b/packages/pg-query-stream/test/concat.ts
@@ -1,14 +1,13 @@
-var assert = require('assert')
-var concat = require('concat-stream')
-var through = require('through')
-var helper = require('./helper')
-
-var QueryStream = require('../')
+import assert from 'assert'
+import concat from 'concat-stream'
+import through from 'through'
+import helper from './helper'
+import QueryStream from '../src'
 
 helper('concat', function (client) {
   it('concats correctly', function (done) {
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
-    var query = client.query(stream)
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
+    const query = client.query(stream)
     query
       .pipe(
         through(function (row) {
@@ -17,7 +16,7 @@ helper('concat', function (client) {
       )
       .pipe(
         concat(function (result) {
-          var total = result.reduce(function (prev, cur) {
+          const total = result.reduce(function (prev, cur) {
             return prev + cur
           })
           assert.equal(total, 20100)
diff --git a/packages/pg-query-stream/test/config.js b/packages/pg-query-stream/test/config.js
deleted file mode 100644
index 061fb1153..000000000
--- a/packages/pg-query-stream/test/config.js
+++ /dev/null
@@ -1,26 +0,0 @@
-var assert = require('assert')
-var QueryStream = require('../')
-
-describe('stream config options', () => {
-  // this is mostly for backwards compatability.
-  it('sets readable.highWaterMark based on batch size', () => {
-    var stream = new QueryStream('SELECT NOW()', [], {
-      batchSize: 88,
-    })
-    assert.equal(stream._readableState.highWaterMark, 88)
-  })
-
-  it('sets readable.highWaterMark based on highWaterMark config', () => {
-    var stream = new QueryStream('SELECT NOW()', [], {
-      highWaterMark: 88,
-    })
-
-    assert.equal(stream._readableState.highWaterMark, 88)
-  })
-
-  it('defaults to 100 for highWaterMark', () => {
-    var stream = new QueryStream('SELECT NOW()', [])
-
-    assert.equal(stream._readableState.highWaterMark, 100)
-  })
-})
diff --git a/packages/pg-query-stream/test/config.ts b/packages/pg-query-stream/test/config.ts
new file mode 100644
index 000000000..024b3d129
--- /dev/null
+++ b/packages/pg-query-stream/test/config.ts
@@ -0,0 +1,26 @@
+import assert from 'assert'
+import QueryStream from '../src'
+
+describe('stream config options', () => {
+  // this is mostly for backwards compatibility.
+  it('sets readable.highWaterMark based on batch size', () => {
+    const stream = new QueryStream('SELECT NOW()', [], {
+      batchSize: 88,
+    })
+    assert.equal(stream.readableHighWaterMark, 88)
+  })
+
+  it('sets readable.highWaterMark based on highWaterMark config', () => {
+    const stream = new QueryStream('SELECT NOW()', [], {
+      highWaterMark: 88,
+    })
+
+    assert.equal(stream.readableHighWaterMark, 88)
+  })
+
+  it('defaults to 100 for highWaterMark', () => {
+    const stream = new QueryStream('SELECT NOW()', [])
+
+    assert.equal(stream.readableHighWaterMark, 100)
+  })
+})
diff --git a/packages/pg-query-stream/test/empty-query.js b/packages/pg-query-stream/test/empty-query.ts
similarity index 82%
rename from packages/pg-query-stream/test/empty-query.js
rename to packages/pg-query-stream/test/empty-query.ts
index 25f7d6956..68f137fe0 100644
--- a/packages/pg-query-stream/test/empty-query.js
+++ b/packages/pg-query-stream/test/empty-query.ts
@@ -1,6 +1,5 @@
-const assert = require('assert')
-const helper = require('./helper')
-const QueryStream = require('../')
+import helper from './helper'
+import QueryStream from '../src'
 
 helper('empty-query', function (client) {
   it('handles empty query', function (done) {
diff --git a/packages/pg-query-stream/test/error.js b/packages/pg-query-stream/test/error.ts
similarity index 67%
rename from packages/pg-query-stream/test/error.js
rename to packages/pg-query-stream/test/error.ts
index 0b732923d..c92cd0091 100644
--- a/packages/pg-query-stream/test/error.js
+++ b/packages/pg-query-stream/test/error.ts
@@ -1,12 +1,11 @@
-var assert = require('assert')
-var helper = require('./helper')
-
-var QueryStream = require('../')
+import assert from 'assert'
+import helper from './helper'
+import QueryStream from '../src'
 
 helper('error', function (client) {
   it('receives error on stream', function (done) {
-    var stream = new QueryStream('SELECT * FROM asdf num', [])
-    var query = client.query(stream)
+    const stream = new QueryStream('SELECT * FROM asdf num', [])
+    const query = client.query(stream)
     query
       .on('error', function (err) {
         assert(err)
diff --git a/packages/pg-query-stream/test/fast-reader.js b/packages/pg-query-stream/test/fast-reader.ts
similarity index 69%
rename from packages/pg-query-stream/test/fast-reader.js
rename to packages/pg-query-stream/test/fast-reader.ts
index 4c6f31f95..5c0c0214a 100644
--- a/packages/pg-query-stream/test/fast-reader.js
+++ b/packages/pg-query-stream/test/fast-reader.ts
@@ -1,14 +1,14 @@
-var assert = require('assert')
-var helper = require('./helper')
-var QueryStream = require('../')
+import assert from 'assert'
+import helper from './helper'
+import QueryStream from '../src'
 
 helper('fast reader', function (client) {
   it('works', function (done) {
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
-    var query = client.query(stream)
-    var result = []
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
+    const query = client.query(stream)
+    const result = []
     stream.on('readable', function () {
-      var res = stream.read()
+      let res = stream.read()
       while (res) {
         if (result.length !== 201) {
           assert(res, 'should not return null on evented reader')
@@ -24,7 +24,7 @@ helper('fast reader', function (client) {
       }
     })
     stream.on('end', function () {
-      var total = result.reduce(function (prev, cur) {
+      const total = result.reduce(function (prev, cur) {
         return prev + cur
       })
       assert.equal(total, 20100)
diff --git a/packages/pg-query-stream/test/helper.js b/packages/pg-query-stream/test/helper.ts
similarity index 68%
rename from packages/pg-query-stream/test/helper.js
rename to packages/pg-query-stream/test/helper.ts
index ad21d6ea2..9e9b63a94 100644
--- a/packages/pg-query-stream/test/helper.js
+++ b/packages/pg-query-stream/test/helper.ts
@@ -1,7 +1,8 @@
-var pg = require('pg')
-module.exports = function (name, cb) {
+import pg from 'pg'
+
+export default function (name, cb) {
   describe(name, function () {
-    var client = new pg.Client()
+    const client = new pg.Client()
 
     before(function (done) {
       client.connect(done)
diff --git a/packages/pg-query-stream/test/instant.js b/packages/pg-query-stream/test/instant.js
deleted file mode 100644
index 0939753bb..000000000
--- a/packages/pg-query-stream/test/instant.js
+++ /dev/null
@@ -1,17 +0,0 @@
-var assert = require('assert')
-var concat = require('concat-stream')
-
-var QueryStream = require('../')
-
-require('./helper')('instant', function (client) {
-  it('instant', function (done) {
-    var query = new QueryStream('SELECT pg_sleep(1)', [])
-    var stream = client.query(query)
-    stream.pipe(
-      concat(function (res) {
-        assert.equal(res.length, 1)
-        done()
-      })
-    )
-  })
-})
diff --git a/packages/pg-query-stream/test/instant.ts b/packages/pg-query-stream/test/instant.ts
new file mode 100644
index 000000000..da4fcad9e
--- /dev/null
+++ b/packages/pg-query-stream/test/instant.ts
@@ -0,0 +1,17 @@
+import helper from './helper'
+import assert from 'assert'
+import concat from 'concat-stream'
+import QueryStream from '../src'
+
+helper('instant', function (client) {
+  it('instant', function (done) {
+    const query = new QueryStream('SELECT pg_sleep(1)', [])
+    const stream = client.query(query)
+    stream.pipe(
+      concat(function (res) {
+        assert.equal(res.length, 1)
+        done()
+      })
+    )
+  })
+})
diff --git a/packages/pg-query-stream/test/issue-3.js b/packages/pg-query-stream/test/issue-3.ts
similarity index 73%
rename from packages/pg-query-stream/test/issue-3.js
rename to packages/pg-query-stream/test/issue-3.ts
index 7b467a3b3..8c2c04455 100644
--- a/packages/pg-query-stream/test/issue-3.js
+++ b/packages/pg-query-stream/test/issue-3.ts
@@ -1,8 +1,9 @@
-var pg = require('pg')
-var QueryStream = require('../')
+import pg from 'pg'
+import QueryStream from '../src'
+
 describe('end semantics race condition', function () {
   before(function (done) {
-    var client = new pg.Client()
+    const client = new pg.Client()
     client.connect()
     client.on('drain', client.end.bind(client))
     client.on('end', done)
@@ -10,14 +11,14 @@ describe('end semantics race condition', function () {
     client.query('create table IF NOT EXISTS c(id int primary key references p)')
   })
   it('works', function (done) {
-    var client1 = new pg.Client()
+    const client1 = new pg.Client()
     client1.connect()
-    var client2 = new pg.Client()
+    const client2 = new pg.Client()
     client2.connect()
 
-    var qr = new QueryStream('INSERT INTO p DEFAULT VALUES RETURNING id')
+    const qr = new QueryStream('INSERT INTO p DEFAULT VALUES RETURNING id')
     client1.query(qr)
-    var id = null
+    let id = null
     qr.on('data', function (row) {
       id = row.id
     })
diff --git a/packages/pg-query-stream/test/passing-options.js b/packages/pg-query-stream/test/passing-options.ts
similarity index 62%
rename from packages/pg-query-stream/test/passing-options.js
rename to packages/pg-query-stream/test/passing-options.ts
index 858767de2..7aa924a04 100644
--- a/packages/pg-query-stream/test/passing-options.js
+++ b/packages/pg-query-stream/test/passing-options.ts
@@ -1,12 +1,12 @@
-var assert = require('assert')
-var helper = require('./helper')
-var QueryStream = require('../')
+import assert from 'assert'
+import helper from './helper'
+import QueryStream from '../src'
 
 helper('passing options', function (client) {
   it('passes row mode array', function (done) {
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 10) num', [], { rowMode: 'array' })
-    var query = client.query(stream)
-    var result = []
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 10) num', [], { rowMode: 'array' })
+    const query = client.query(stream)
+    const result = []
     query.on('data', (datum) => {
       result.push(datum)
     })
@@ -21,9 +21,9 @@ helper('passing options', function (client) {
     const types = {
       getTypeParser: () => (string) => string,
     }
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 10) num', [], { types })
-    var query = client.query(stream)
-    var result = []
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 10) num', [], { types })
+    const query = client.query(stream)
+    const result = []
     query.on('data', (datum) => {
       result.push(datum)
     })
diff --git a/packages/pg-query-stream/test/pauses.js b/packages/pg-query-stream/test/pauses.js
deleted file mode 100644
index 3da9a0b07..000000000
--- a/packages/pg-query-stream/test/pauses.js
+++ /dev/null
@@ -1,23 +0,0 @@
-var concat = require('concat-stream')
-var tester = require('stream-tester')
-var JSONStream = require('JSONStream')
-
-var QueryStream = require('../')
-
-require('./helper')('pauses', function (client) {
-  it('pauses', function (done) {
-    this.timeout(5000)
-    var stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [200], { batchSize: 2, highWaterMark: 2 })
-    var query = client.query(stream)
-    var pauser = tester.createPauseStream(0.1, 100)
-    query
-      .pipe(JSONStream.stringify())
-      .pipe(pauser)
-      .pipe(
-        concat(function (json) {
-          JSON.parse(json)
-          done()
-        })
-      )
-  })
-})
diff --git a/packages/pg-query-stream/test/pauses.ts b/packages/pg-query-stream/test/pauses.ts
new file mode 100644
index 000000000..daf8347af
--- /dev/null
+++ b/packages/pg-query-stream/test/pauses.ts
@@ -0,0 +1,26 @@
+import helper from './helper'
+import concat from 'concat-stream'
+import tester from 'stream-tester'
+import JSONStream from 'JSONStream'
+import QueryStream from '../src'
+
+helper('pauses', function (client) {
+  it('pauses', function (done) {
+    this.timeout(5000)
+    const stream = new QueryStream('SELECT * FROM generate_series(0, $1) num', [200], {
+      batchSize: 2,
+      highWaterMark: 2,
+    })
+    const query = client.query(stream)
+    const pauser = tester.createPauseStream(0.1, 100)
+    query
+      .pipe(JSONStream.stringify())
+      .pipe(pauser)
+      .pipe(
+        concat(function (json) {
+          JSON.parse(json)
+          done()
+        })
+      )
+  })
+})
diff --git a/packages/pg-query-stream/test/slow-reader.js b/packages/pg-query-stream/test/slow-reader.ts
similarity index 61%
rename from packages/pg-query-stream/test/slow-reader.js
rename to packages/pg-query-stream/test/slow-reader.ts
index 3978f3004..a62c0c20c 100644
--- a/packages/pg-query-stream/test/slow-reader.js
+++ b/packages/pg-query-stream/test/slow-reader.ts
@@ -1,10 +1,10 @@
-var helper = require('./helper')
-var QueryStream = require('../')
-var concat = require('concat-stream')
+import helper from './helper'
+import QueryStream from '../src'
+import concat from 'concat-stream'
 
-var Transform = require('stream').Transform
+import { Transform } from 'stream'
 
-var mapper = new Transform({ objectMode: true })
+const mapper = new Transform({ objectMode: true })
 
 mapper._transform = function (obj, enc, cb) {
   this.push(obj)
@@ -14,7 +14,7 @@ mapper._transform = function (obj, enc, cb) {
 helper('slow reader', function (client) {
   it('works', function (done) {
     this.timeout(50000)
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 201) num', [], {
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 201) num', [], {
       highWaterMark: 100,
       batchSize: 50,
     })
diff --git a/packages/pg-query-stream/test/stream-tester-timestamp.js b/packages/pg-query-stream/test/stream-tester-timestamp.js
deleted file mode 100644
index ce989cc3f..000000000
--- a/packages/pg-query-stream/test/stream-tester-timestamp.js
+++ /dev/null
@@ -1,25 +0,0 @@
-var QueryStream = require('../')
-var spec = require('stream-spec')
-var assert = require('assert')
-
-require('./helper')('stream tester timestamp', function (client) {
-  it('should not warn about max listeners', function (done) {
-    var sql = "SELECT * FROM generate_series('1983-12-30 00:00'::timestamp, '2013-12-30 00:00', '1 years')"
-    var stream = new QueryStream(sql, [])
-    var ended = false
-    var query = client.query(stream)
-    query.on('end', function () {
-      ended = true
-    })
-    spec(query).readable().pausable({ strict: true }).validateOnExit()
-    var checkListeners = function () {
-      assert(stream.listeners('end').length < 10)
-      if (!ended) {
-        setImmediate(checkListeners)
-      } else {
-        done()
-      }
-    }
-    checkListeners()
-  })
-})
diff --git a/packages/pg-query-stream/test/stream-tester-timestamp.ts b/packages/pg-query-stream/test/stream-tester-timestamp.ts
new file mode 100644
index 000000000..9819ba491
--- /dev/null
+++ b/packages/pg-query-stream/test/stream-tester-timestamp.ts
@@ -0,0 +1,26 @@
+import helper from './helper'
+import QueryStream from '../src'
+import spec from 'stream-spec'
+import assert from 'assert'
+
+helper('stream tester timestamp', function (client) {
+  it('should not warn about max listeners', function (done) {
+    const sql = "SELECT * FROM generate_series('1983-12-30 00:00'::timestamp, '2013-12-30 00:00', '1 years')"
+    const stream = new QueryStream(sql, [])
+    let ended = false
+    const query = client.query(stream)
+    query.on('end', function () {
+      ended = true
+    })
+    spec(query).readable().pausable({ strict: true }).validateOnExit()
+    const checkListeners = function () {
+      assert(stream.listeners('end').length < 10)
+      if (!ended) {
+        setImmediate(checkListeners)
+      } else {
+        done()
+      }
+    }
+    checkListeners()
+  })
+})
diff --git a/packages/pg-query-stream/test/stream-tester.js b/packages/pg-query-stream/test/stream-tester.js
deleted file mode 100644
index f5ab2e372..000000000
--- a/packages/pg-query-stream/test/stream-tester.js
+++ /dev/null
@@ -1,12 +0,0 @@
-var spec = require('stream-spec')
-
-var QueryStream = require('../')
-
-require('./helper')('stream tester', function (client) {
-  it('passes stream spec', function (done) {
-    var stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
-    var query = client.query(stream)
-    spec(query).readable().pausable({ strict: true }).validateOnExit()
-    stream.on('end', done)
-  })
-})
diff --git a/packages/pg-query-stream/test/stream-tester.ts b/packages/pg-query-stream/test/stream-tester.ts
new file mode 100644
index 000000000..01c68275c
--- /dev/null
+++ b/packages/pg-query-stream/test/stream-tester.ts
@@ -0,0 +1,12 @@
+import spec from 'stream-spec'
+import helper from './helper'
+import QueryStream from '../src'
+
+helper('stream tester', function (client) {
+  it('passes stream spec', function (done) {
+    const stream = new QueryStream('SELECT * FROM generate_series(0, 200) num', [])
+    const query = client.query(stream)
+    spec(query).readable().pausable({ strict: true }).validateOnExit()
+    stream.on('end', done)
+  })
+})
diff --git a/packages/pg-query-stream/tsconfig.json b/packages/pg-query-stream/tsconfig.json
new file mode 100644
index 000000000..15b962dd9
--- /dev/null
+++ b/packages/pg-query-stream/tsconfig.json
@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "strict": false,
+    "target": "es6",
+    "noImplicitAny": false,
+    "moduleResolution": "node",
+    "sourceMap": true,
+    "pretty": true,
+    "outDir": "dist",
+    "incremental": true,
+    "baseUrl": ".",
+    "declaration": true,
+    "types": [
+      "node",
+      "pg",
+      "mocha",
+      "chai"
+    ]
+  },
+  "include": [
+    "src/**/*"
+  ]
+}
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 000000000..53fb70c6e
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,12 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "incremental": true,
+    "composite": true
+  },
+  "include": [],
+  "references": [
+    {"path": "./packages/pg-query-stream"},
+    {"path": "./packages/pg-protocol"}
+  ]
+}
diff --git a/yarn.lock b/yarn.lock
index 04b915afa..a9273e00c 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -941,7 +941,7 @@
   dependencies:
     "@types/node" ">= 8"
 
-"@types/chai@^4.2.7":
+"@types/chai@^4.2.13", "@types/chai@^4.2.7":
   version "4.2.13"
   resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.2.13.tgz#8a3801f6655179d1803d81e94a2e4aaf317abd16"
   integrity sha512-o3SGYRlOpvLFpwJA6Sl1UPOwKFEvE4FxTEB/c9XHI2whdnd4kmPVkNLL8gY4vWGBxWWDumzLbKsAhEH5SKn37Q==
@@ -974,21 +974,44 @@
   resolved "https://registry.yarnpkg.com/@types/mocha/-/mocha-5.2.7.tgz#315d570ccb56c53452ff8638738df60726d5b6ea"
   integrity sha512-NYrtPht0wGzhwe9+/idPaBB+TqkY9AhTvOLMkThm0IoEfLaiVQZwBwyJ5puCkO3AUCWrmcoePjp2mbFocKy4SQ==
 
+"@types/mocha@^8.0.3":
+  version "8.0.3"
+  resolved "https://registry.yarnpkg.com/@types/mocha/-/mocha-8.0.3.tgz#51b21b6acb6d1b923bbdc7725c38f9f455166402"
+  integrity sha512-vyxR57nv8NfcU0GZu8EUXZLTbCMupIUwy95LJ6lllN+JRPG25CwMHoB1q5xKh8YKhQnHYRAn4yW2yuHbf/5xgg==
+
 "@types/node@*", "@types/node@>= 8":
-  version "14.11.8"
-  resolved "https://registry.yarnpkg.com/@types/node/-/node-14.11.8.tgz#fe2012f2355e4ce08bca44aeb3abbb21cf88d33f"
-  integrity sha512-KPcKqKm5UKDkaYPTuXSx8wEP7vE9GnuaXIZKijwRYcePpZFDVuy2a57LarFKiORbHOuTOOwYzxVxcUzsh2P2Pw==
+  version "12.12.21"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-12.12.21.tgz#aa44a6363291c7037111c47e4661ad210aded23f"
+  integrity sha512-8sRGhbpU+ck1n0PGAUgVrWrWdjSW2aqNeyC15W88GRsMpSwzv6RJGlLhE7s2RhVSOdyDmxbqlWSeThq4/7xqlA==
 
 "@types/node@^12.12.21":
   version "12.12.67"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-12.12.67.tgz#4f86badb292e822e3b13730a1f9713ed2377f789"
   integrity sha512-R48tgL2izApf+9rYNH+3RBMbRpPeW3N8f0I9HMhggeq4UXwBDqumJ14SDs4ctTMhG11pIOduZ4z3QWGOiMc9Vg==
 
+"@types/node@^14.0.0":
+  version "14.11.8"
+  resolved "https://registry.yarnpkg.com/@types/node/-/node-14.11.8.tgz#fe2012f2355e4ce08bca44aeb3abbb21cf88d33f"
+  integrity sha512-KPcKqKm5UKDkaYPTuXSx8wEP7vE9GnuaXIZKijwRYcePpZFDVuy2a57LarFKiORbHOuTOOwYzxVxcUzsh2P2Pw==
+
 "@types/normalize-package-data@^2.4.0":
   version "2.4.0"
   resolved "https://registry.yarnpkg.com/@types/normalize-package-data/-/normalize-package-data-2.4.0.tgz#e486d0d97396d79beedd0a6e33f4534ff6b4973e"
   integrity sha512-f5j5b/Gf71L+dbqxIpQ4Z2WlmI/mPJ0fOkGGmFgtb6sAu97EPczzbS3/tJKxmcYDj55OX6ssqwDAWOHIYDRDGA==
 
+"@types/pg-types@*":
+  version "1.11.5"
+  resolved "https://registry.yarnpkg.com/@types/pg-types/-/pg-types-1.11.5.tgz#1eebbe62b6772fcc75c18957a90f933d155e005b"
+  integrity sha512-L8ogeT6vDzT1vxlW3KITTCt+BVXXVkLXfZ/XNm6UqbcJgxf+KPO7yjWx7dQQE8RW07KopL10x2gNMs41+IkMGQ==
+
+"@types/pg@^7.14.5":
+  version "7.14.5"
+  resolved "https://registry.yarnpkg.com/@types/pg/-/pg-7.14.5.tgz#07638c7aa69061abe4be31267028cc5c3fc35f98"
+  integrity sha512-wqTKZmqkqXd1YiVRBT2poRrMIojwEi2bKTAAjUX6nEbzr98jc3cfR/7o7ZtubhH5xT7YJ6LRdRr1GZOgs8OUjg==
+  dependencies:
+    "@types/node" "*"
+    "@types/pg-types" "*"
+
 "@typescript-eslint/eslint-plugin@^4.4.0":
   version "4.4.0"
   resolved "https://registry.yarnpkg.com/@typescript-eslint/eslint-plugin/-/eslint-plugin-4.4.0.tgz#0321684dd2b902c89128405cf0385e9fe8561934"
@@ -6096,10 +6119,10 @@ typedarray@^0.0.6:
   resolved "https://registry.yarnpkg.com/typedarray/-/typedarray-0.0.6.tgz#867ac74e3864187b1d3d47d996a78ec5c8830777"
   integrity sha1-hnrHTjhkGHsdPUfZlqeOxciDB3c=
 
-typescript@^3.7.3:
-  version "3.9.7"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.7.tgz#98d600a5ebdc38f40cb277522f12dc800e9e25fa"
-  integrity sha512-BLbiRkiBzAwsjut4x/dsibSTB6yWpwT5qWmC2OfuCg3GgVQCSgMs4vEctYPhsaGtd0AeuuHMkjZ2h2WG8MSzRw==
+typescript@^4.0.3:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-4.0.3.tgz#153bbd468ef07725c1df9c77e8b453f8d36abba5"
+  integrity sha512-tEu6DGxGgRJPb/mVPIZ48e69xCn2yRmCgYmDugAVwmJ6o+0u1RI18eO7E7WBTLYLaEVVOhwQmcdhQHweux/WPg==
 
 uglify-js@^3.1.4:
   version "3.11.1"