diff --git a/src/adapters/action/dispatcher-http-hook-mastodon.ts b/src/adapters/action/dispatcher-http-hook-mastodon.ts
index 72ee9478..67ecd17e 100644
--- a/src/adapters/action/dispatcher-http-hook-mastodon.ts
+++ b/src/adapters/action/dispatcher-http-hook-mastodon.ts
@@ -58,7 +58,7 @@ async function waitForMediaAttachment(
   let media: mastodon.v1.MediaAttachment | undefined;
   const signal = AbortSignal.timeout(timeout);
 
-  while (media == undefined) {
+  while (!media) {
     if (signal.aborted) {
       throw new MastoTimeoutError(`Media processing timed out of ${timeout}ms`);
     }
@@ -70,7 +70,7 @@ async function waitForMediaAttachment(
         `/api/v1/media/${id}`,
       );
 
-      if (processing.url != undefined) {
+      if (processing.url) {
         media = processing;
       }
     } catch (error) {
diff --git a/src/adapters/action/dispatcher-http.ts b/src/adapters/action/dispatcher-http.ts
index e8b9b668..22bf026f 100644
--- a/src/adapters/action/dispatcher-http.ts
+++ b/src/adapters/action/dispatcher-http.ts
@@ -16,7 +16,7 @@ export class HttpActionDispatcher implements ActionDispatcher<HttpAction> {
   ) {}
 
   dispatch<T>(action: HttpAction): T | Promise<T> {
-    if (this.hook != undefined) {
+    if (this.hook) {
       action = this.hook.beforeDispatch(action);
     }
 
diff --git a/src/adapters/action/paginator-http.ts b/src/adapters/action/paginator-http.ts
index 951c4257..c959b3ee 100644
--- a/src/adapters/action/paginator-http.ts
+++ b/src/adapters/action/paginator-http.ts
@@ -15,7 +15,7 @@ export class PaginatorHttp<Entity, Params = undefined>
   ) {}
 
   async next(): Promise<IteratorResult<Entity, undefined>> {
-    if (this.nextPath == undefined) {
+    if (!this.nextPath) {
       return { done: true, value: undefined };
     }
 
@@ -98,12 +98,12 @@ export class PaginatorHttp<Entity, Params = undefined>
   }
 
   private getLink(value?: string | null): URL | undefined {
-    if (value == undefined) {
+    if (!value) {
       return;
     }
 
     const parsed = parseLinkHeader(value).get(this.direction);
-    if (parsed == undefined) {
+    if (!parsed) {
       return;
     }
 
diff --git a/src/adapters/action/proxy.ts b/src/adapters/action/proxy.ts
index 4011d696..eba0af3a 100644
--- a/src/adapters/action/proxy.ts
+++ b/src/adapters/action/proxy.ts
@@ -84,7 +84,7 @@ const apply =
     const action = context.pop();
 
     /* istanbul ignore next */
-    if (action == undefined) {
+    if (!action) {
       throw new Error("No action specified");
     }
 
diff --git a/src/adapters/config/http-config.ts b/src/adapters/config/http-config.ts
index 3a969a4a..a94f1f6c 100644
--- a/src/adapters/config/http-config.ts
+++ b/src/adapters/config/http-config.ts
@@ -55,7 +55,7 @@ export class HttpConfigImpl implements HttpConfig {
 
     if (typeof params === "string") {
       url.search = params;
-    } else if (params != undefined) {
+    } else if (params) {
       url.search = this.serializer.serialize("querystring", params);
     }
 
@@ -81,7 +81,7 @@ export class HttpConfigImpl implements HttpConfig {
   ): AbortSignal {
     const signals: AbortSignal[] = [];
 
-    if (this.props.timeout != undefined) {
+    if (this.props.timeout) {
       signals.push(AbortSignal.timeout(this.props.timeout));
     }
 
@@ -89,7 +89,7 @@ export class HttpConfigImpl implements HttpConfig {
       signals.push(this.props.requestInit.signal);
     }
 
-    if (signal != undefined) {
+    if (signal) {
       signals.push(signal);
     }
 
diff --git a/src/adapters/http/http-native-impl.spec.ts b/src/adapters/http/http-native-impl.spec.ts
index 52f36c4f..9473adf1 100644
--- a/src/adapters/http/http-native-impl.spec.ts
+++ b/src/adapters/http/http-native-impl.spec.ts
@@ -9,19 +9,29 @@ import { HttpNativeImpl } from "./http-native-impl";
 
 describe("HttpNativeImpl", () => {
   it("timeouts", async () => {
+    const server = node_http.createServer((_, res) => {
+      res.writeHead(200, { "Content-Type": "application/json" });
+      res.end("{}");
+    });
+
+    const port = await getPort();
+    server.listen(port);
+
     const serializer = new SerializerNativeImpl();
     const http = new HttpNativeImpl(
       serializer,
       new HttpConfigImpl(
         {
-          url: "https://example.com",
-          timeout: 0,
+          url: `http://localhost:${port}`,
+          timeout: 1,
         },
         serializer,
       ),
     );
 
-    await expect(() => http.get("/")).rejects.toThrowError(MastoTimeoutError);
+    await expect(() => http.get("/")).rejects.toThrow(MastoTimeoutError);
+
+    server.close();
   });
 
   it("throws an error if server returned non-JSON", async () => {
diff --git a/src/adapters/http/http-native-impl.ts b/src/adapters/http/http-native-impl.ts
index 6beb843b..fd0c61ad 100644
--- a/src/adapters/http/http-native-impl.ts
+++ b/src/adapters/http/http-native-impl.ts
@@ -40,7 +40,7 @@ export class HttpNativeImpl extends BaseHttp implements Http {
 
       const text = await response.text();
       const encoding = getEncoding(response.headers);
-      if (encoding == undefined) {
+      if (!encoding) {
         throw new MastoUnexpectedError(
           "The server returned data with an unknown encoding.",
         );
@@ -89,7 +89,7 @@ export class HttpNativeImpl extends BaseHttp implements Http {
   private async createError(error: unknown): Promise<unknown> {
     if (error instanceof Response) {
       const encoding = getEncoding(error.headers);
-      if (encoding == undefined) {
+      if (!encoding) {
         throw new MastoUnexpectedError(
           "The server returned data with an unknown encoding. The server may be down.",
         );
diff --git a/src/adapters/serializers/flatten.ts b/src/adapters/serializers/flatten.ts
index fc176105..b6d31c8a 100644
--- a/src/adapters/serializers/flatten.ts
+++ b/src/adapters/serializers/flatten.ts
@@ -46,7 +46,7 @@ export const flattenForRailsQueryString = (object: unknown): string => {
   });
 
   return flatten(object)
-    .filter(([, v]) => v != undefined)
+    .filter(([, v]) => !!v)
     .map(([k, v]) => `${k}=${encodeURIComponent(v as string)}`)
     .join("&");
 };
diff --git a/src/adapters/ws/async-iterable.ts b/src/adapters/ws/async-iterable.ts
index ee2ddec7..458ee343 100644
--- a/src/adapters/ws/async-iterable.ts
+++ b/src/adapters/ws/async-iterable.ts
@@ -8,7 +8,7 @@ export async function* toAsyncIterable(
 ): AsyncIterableIterator<WebSocket.MessageEvent> {
   const handleClose = async (e: WebSocket.CloseEvent) => {
     /* istanbul ignore next */
-    if (events.return == undefined) {
+    if (!events.return) {
       throw new MastoUnexpectedError("events.return is undefined");
     }
     await events.return(e);
@@ -16,7 +16,7 @@ export async function* toAsyncIterable(
 
   const handleError = async (e: WebSocket.ErrorEvent) => {
     /* istanbul ignore next */
-    if (events.return == undefined) {
+    if (!events.return) {
       throw new MastoUnexpectedError("events.return is undefined");
     }
     await events.return(e);
diff --git a/src/adapters/ws/web-socket-connector.ts b/src/adapters/ws/web-socket-connector.ts
index 9a3077fd..97b2a06b 100644
--- a/src/adapters/ws/web-socket-connector.ts
+++ b/src/adapters/ws/web-socket-connector.ts
@@ -37,7 +37,7 @@ export class WebSocketConnectorImpl implements WebSocketConnector {
       throw new MastoWebSocketError("WebSocket closed");
     }
 
-    if (this.ws != undefined) {
+    if (this.ws) {
       return Promise.resolve(this.ws);
     }
 
diff --git a/src/adapters/ws/web-socket-subscription.ts b/src/adapters/ws/web-socket-subscription.ts
index 512dc167..e421624f 100644
--- a/src/adapters/ws/web-socket-subscription.ts
+++ b/src/adapters/ws/web-socket-subscription.ts
@@ -56,7 +56,7 @@ export class WebSocketSubscription implements mastodon.streaming.Subscription {
   }
 
   unsubscribe(): void {
-    if (this.connection == undefined) {
+    if (!this.connection) {
       return;
     }