diff --git a/src/create-infura-middleware.ts b/src/create-infura-middleware.ts
index 1115f98..dd1edb8 100644
--- a/src/create-infura-middleware.ts
+++ b/src/create-infura-middleware.ts
@@ -1,23 +1,25 @@
-import type { PendingJsonRpcResponse } from 'json-rpc-engine';
-import { createAsyncMiddleware } from 'json-rpc-engine';
 import type { EthereumRpcError } from 'eth-rpc-errors';
 import { ethErrors } from 'eth-rpc-errors';
+import { createAsyncMiddleware } from 'json-rpc-engine';
+import type { PendingJsonRpcResponse } from 'json-rpc-engine';
+// eslint-disable-next-line @typescript-eslint/no-shadow
 import fetch from 'node-fetch';
+
+import { fetchConfigFromReq } from './fetch-config-from-req';
+import { projectLogger, createModuleLogger } from './logging-utils';
 import type {
   ExtendedJsonRpcRequest,
   InfuraJsonRpcSupportedNetwork,
   RequestHeaders,
 } from './types';
-import { fetchConfigFromReq } from './fetch-config-from-req';
-import { projectLogger, createModuleLogger } from './logging-utils';
 
-export interface CreateInfuraMiddlewareOptions {
+export type CreateInfuraMiddlewareOptions = {
   network?: InfuraJsonRpcSupportedNetwork;
   maxAttempts?: number;
   source?: string;
   projectId: string;
   headers?: Record<string, string>;
-}
+};
 
 const log = createModuleLogger(projectLogger, 'create-infura-middleware');
 const RETRIABLE_ERRORS = [
@@ -58,6 +60,7 @@ export function createInfuraMiddleware({
   }
 
   if (!headers || typeof headers !== 'object') {
+    // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
     throw new Error(`Invalid value for 'headers': "${headers}"`);
   }
 
@@ -104,7 +107,7 @@ export function createInfuraMiddleware({
             res,
             err,
           );
-          const errMsg = `InfuraProvider - cannot complete request. All retries exhausted.\nOriginal Error:\n${err.toString()}\n\n`;
+          const errMsg = `InfuraProvider - cannot complete request. All retries exhausted.\nOriginal Error:\n${err.toString() as string}\n\n`;
           const retriesExhaustedErr = new Error(errMsg);
           throw retriesExhaustedErr;
         }
@@ -240,7 +243,7 @@ function isRetriableError(err: any): boolean {
  * @param length - The number of milliseconds to wait.
  * @returns A promise that resolves after the given time has elapsed.
  */
-function timeout(length: number): Promise<void> {
+async function timeout(length: number): Promise<void> {
   return new Promise((resolve) => {
     setTimeout(resolve, length);
   });
diff --git a/src/create-provider.ts b/src/create-provider.ts
index a28e9e0..9c9d2c7 100644
--- a/src/create-provider.ts
+++ b/src/create-provider.ts
@@ -1,10 +1,9 @@
-import { JsonRpcEngine } from 'json-rpc-engine';
 import { providerFromEngine } from '@metamask/eth-json-rpc-provider';
 import type { SafeEventEmitterProvider } from '@metamask/eth-json-rpc-provider';
-import {
-  createInfuraMiddleware,
-  CreateInfuraMiddlewareOptions,
-} from './create-infura-middleware';
+import { JsonRpcEngine } from 'json-rpc-engine';
+
+import type { CreateInfuraMiddlewareOptions } from './create-infura-middleware';
+import { createInfuraMiddleware } from './create-infura-middleware';
 
 /**
  * Creates a provider (as defined in
diff --git a/src/fetch-config-from-req.test.ts b/src/fetch-config-from-req.test.ts
index 6802b1d..4dccbf5 100644
--- a/src/fetch-config-from-req.test.ts
+++ b/src/fetch-config-from-req.test.ts
@@ -17,9 +17,7 @@ describe('fetchConfigFromReq', () => {
       body: JSON.parse(fetchParams.body),
     };
 
-    expect(fetchUrl).toStrictEqual(
-      'https://mainnet.infura.io/v3/abcdef1234567890',
-    );
+    expect(fetchUrl).toBe('https://mainnet.infura.io/v3/abcdef1234567890');
 
     expect(decodedFetchParams).toStrictEqual({
       method: 'POST',
@@ -53,9 +51,7 @@ describe('fetchConfigFromReq', () => {
       body: JSON.parse(fetchParams.body),
     };
 
-    expect(fetchUrl).toStrictEqual(
-      'https://mainnet.infura.io/v3/abcdef1234567890',
-    );
+    expect(fetchUrl).toBe('https://mainnet.infura.io/v3/abcdef1234567890');
 
     expect(decodedFetchParams).toStrictEqual({
       method: 'POST',
@@ -91,9 +87,7 @@ describe('fetchConfigFromReq', () => {
       body: JSON.parse(fetchParams.body),
     };
 
-    expect(fetchUrl).toStrictEqual(
-      'https://mainnet.infura.io/v3/abcdef1234567890',
-    );
+    expect(fetchUrl).toBe('https://mainnet.infura.io/v3/abcdef1234567890');
 
     expect(decodedFetchParams).toStrictEqual({
       method: 'POST',
@@ -130,9 +124,7 @@ describe('fetchConfigFromReq', () => {
       body: JSON.parse(fetchParams.body),
     };
 
-    expect(fetchUrl).toStrictEqual(
-      'https://mainnet.infura.io/v3/abcdef1234567890',
-    );
+    expect(fetchUrl).toBe('https://mainnet.infura.io/v3/abcdef1234567890');
 
     expect(decodedFetchParams).toStrictEqual({
       method: 'POST',
@@ -167,9 +159,7 @@ describe('fetchConfigFromReq', () => {
       body: JSON.parse(fetchParams.body),
     });
 
-    expect(fetchUrl).toStrictEqual(
-      'https://mainnet.infura.io/v3/abcdef1234567890',
-    );
+    expect(fetchUrl).toBe('https://mainnet.infura.io/v3/abcdef1234567890');
 
     expect(decodedFetchParams.body).toStrictEqual({
       id: 1,
diff --git a/src/fetch-config-from-req.ts b/src/fetch-config-from-req.ts
index e0a31fa..22615d8 100644
--- a/src/fetch-config-from-req.ts
+++ b/src/fetch-config-from-req.ts
@@ -1,18 +1,19 @@
 import type { JsonRpcRequest } from 'json-rpc-engine';
+
 import type {
   ExtendedJsonRpcRequest,
   RequestHeaders,
   InfuraJsonRpcSupportedNetwork,
 } from './types';
 
-interface FetchConfig {
+type FetchConfig = {
   fetchUrl: string;
   fetchParams: {
     method: string;
     headers: RequestHeaders;
     body: string;
   };
-}
+};
 
 /**
  * Determines the arguments to feed into `fetch` in order to make a request to
@@ -44,6 +45,7 @@ export function fetchConfigFromReq({
   req: ExtendedJsonRpcRequest<unknown>;
   source?: string;
 }): FetchConfig {
+  // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
   const requestOrigin = req.origin || 'internal';
   const headers = Object.assign({}, extraHeaders, {
     Accept: 'application/json',
diff --git a/src/types.ts b/src/types.ts
index 1b4748e..b6e3aaa 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -2,7 +2,7 @@ import type { JsonRpcRequest } from 'json-rpc-engine';
 
 export type RequestHeaders = Record<string, string>;
 
-export type ExtendedJsonRpcRequest<T> = JsonRpcRequest<T> & { origin?: string };
+export type ExtendedJsonRpcRequest<Params> = JsonRpcRequest<Params> & { origin?: string };
 
 /**
  * These are networks: