diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7f697b08..f04f4ec5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -15,7 +15,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [12.x, 14.x, 15.x, 16.x]
+        node-version: [18.x, 19.x, 20.x, 22.x]
 
     steps:
       - uses: actions/checkout@v2
diff --git a/package.json b/package.json
index 93214fb8..32333fb0 100644
--- a/package.json
+++ b/package.json
@@ -3,7 +3,7 @@
   "version": "2.2.15",
   "description": "A simple and easy to use client for the Notion API",
   "engines": {
-    "node": ">=12"
+    "node": ">=18"
   },
   "homepage": "https://developers.notion.com/docs/getting-started",
   "bugs": {
@@ -39,10 +39,6 @@
     "build/package.json",
     "build/src/**"
   ],
-  "dependencies": {
-    "@types/node-fetch": "^2.5.10",
-    "node-fetch": "^2.6.1"
-  },
   "devDependencies": {
     "@types/jest": "^28.1.4",
     "@typescript-eslint/eslint-plugin": "^5.39.0",
diff --git a/src/Client.ts b/src/Client.ts
index 338807b9..bbf5b5bc 100644
--- a/src/Client.ts
+++ b/src/Client.ts
@@ -77,12 +77,10 @@ import {
   OauthTokenParameters,
   oauthToken,
 } from "./api-endpoints"
-import nodeFetch from "node-fetch"
 import {
   version as PACKAGE_VERSION,
   name as PACKAGE_NAME,
 } from "../package.json"
-import { SupportedFetch } from "./fetch-types"
 
 export interface ClientOptions {
   auth?: string
@@ -91,7 +89,6 @@ export interface ClientOptions {
   logLevel?: LogLevel
   logger?: Logger
   notionVersion?: string
-  fetch?: SupportedFetch
   /** Silently ignored in the browser */
   agent?: Agent
 }
@@ -121,8 +118,6 @@ export default class Client {
   #prefixUrl: string
   #timeoutMs: number
   #notionVersion: string
-  #fetch: SupportedFetch
-  #agent: Agent | undefined
   #userAgent: string
 
   static readonly defaultNotionVersion = "2022-06-28"
@@ -134,8 +129,6 @@ export default class Client {
     this.#prefixUrl = (options?.baseUrl ?? "https://api.notion.com") + "/v1/"
     this.#timeoutMs = options?.timeoutMs ?? 60_000
     this.#notionVersion = options?.notionVersion ?? Client.defaultNotionVersion
-    this.#fetch = options?.fetch ?? nodeFetch
-    this.#agent = options?.agent
     this.#userAgent = `notionhq-client/${PACKAGE_VERSION}`
   }
 
@@ -204,11 +197,10 @@ export default class Client {
     }
     try {
       const response = await RequestTimeoutError.rejectAfterTimeout(
-        this.#fetch(url.toString(), {
+        fetch(url.toString(), {
           method: method.toUpperCase(),
           headers,
           body: bodyAsJsonString,
-          agent: this.#agent,
         }),
         this.#timeoutMs
       )
diff --git a/src/errors.ts b/src/errors.ts
index cfec919b..9496f0e2 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -1,4 +1,3 @@
-import { SupportedResponse } from "./fetch-types"
 import { isObject } from "./utils"
 import { Assert } from "./type-utils"
 
@@ -125,14 +124,14 @@ class HTTPResponseError<
   readonly name: string = "HTTPResponseError"
   readonly code: Code
   readonly status: number
-  readonly headers: SupportedResponse["headers"]
+  readonly headers: Headers
   readonly body: string
 
   constructor(args: {
     code: Code
     status: number
     message: string
-    headers: SupportedResponse["headers"]
+    headers: Headers
     rawBodyText: string
   }) {
     super(args.message)
@@ -184,7 +183,7 @@ export class UnknownHTTPResponseError extends HTTPResponseError<ClientErrorCode.
   constructor(args: {
     status: number
     message: string | undefined
-    headers: SupportedResponse["headers"]
+    headers: Headers
     rawBodyText: string
   }) {
     super({
@@ -232,7 +231,7 @@ export class APIResponseError extends HTTPResponseError<APIErrorCode> {
 }
 
 export function buildRequestError(
-  response: SupportedResponse,
+  response: Response,
   bodyText: string
 ): APIResponseError | UnknownHTTPResponseError {
   const apiErrorResponseBody = parseAPIErrorResponseBody(bodyText)
diff --git a/src/fetch-types.ts b/src/fetch-types.ts
deleted file mode 100644
index efaf8cfa..00000000
--- a/src/fetch-types.ts
+++ /dev/null
@@ -1,47 +0,0 @@
-import type { Agent } from "http"
-import type { Assert } from "./type-utils"
-import type NodeFetchFn from "node-fetch"
-import type {
-  RequestInfo as NodeFetchRequestInfo,
-  RequestInit as NodeFetchRequestInit,
-  Response as NodeFetchResponse,
-} from "node-fetch"
-
-// The `Supported` types should be kept up to date in order to exactly match what we use in the client. This ensures maximal compatibility with other `fetch` implementations.
-export type SupportedRequestInfo = string
-// We can't assert against the browser or native Node fetch types without complicating the package structure (see #401), so perform a best effort against `node-fetch`, which we use by default.
-type _assertSupportedInfoIsSubtypeOfNodeFetch = Assert<
-  NodeFetchRequestInfo,
-  SupportedRequestInfo
->
-
-export type SupportedRequestInit = {
-  agent?: Agent
-  body?: string
-  headers?: Record<string, string>
-  method?: string
-}
-type _assertSupportedInitIsSubtypeOfNodeFetch = Assert<
-  NodeFetchRequestInit,
-  SupportedRequestInit
->
-
-export type SupportedResponse = {
-  ok: boolean
-  text: () => Promise<string>
-  headers: unknown
-  status: number
-}
-type _assertSupportedResponseIsSubtypeOfNodeFetch = Assert<
-  SupportedResponse,
-  NodeFetchResponse
->
-
-export type SupportedFetch = (
-  url: SupportedRequestInfo,
-  init?: SupportedRequestInit
-) => Promise<SupportedResponse>
-type _assertSupportedFetchIsSubtypeOfNodeFetch = Assert<
-  SupportedFetch,
-  typeof NodeFetchFn
->