diff --git a/lib/reactotron-core-client/package.json b/lib/reactotron-core-client/package.json
index 606153113..f6fddcd8e 100644
--- a/lib/reactotron-core-client/package.json
+++ b/lib/reactotron-core-client/package.json
@@ -74,7 +74,7 @@
     "rollup-plugin-resolve": "0.0.1-predev.1",
     "ts-jest": "^29.1.1",
     "tslib": "^2.6.2",
-    "typescript": "^4.9.5",
+    "typescript": "^5.1.3",
     "ws": "^8.14.2"
   },
   "eslintConfig": {
diff --git a/lib/reactotron-core-client/src/client-options.ts b/lib/reactotron-core-client/src/client-options.ts
index 67d435be3..a74d33ec4 100644
--- a/lib/reactotron-core-client/src/client-options.ts
+++ b/lib/reactotron-core-client/src/client-options.ts
@@ -6,24 +6,24 @@ type BrowserWebSocket = WebSocket
 /**
  * Configuration options for the Reactotron Client.
  */
-export interface ClientOptions<Client> extends LifeCycleMethods {
+export interface ClientOptions<Client> extends Omit<LifeCycleMethods, "onCommand"> {
   /**
    * A function which returns a websocket.
    *
    * This is over-engineered because we need the ability to create different
    * types of websockets for React Native, React, and NodeJS.  :|
    */
-  createSocket?: ((path: string) => BrowserWebSocket) | ((path: string) => NodeWebSocket)
+  createSocket?: ((path: string) => BrowserWebSocket) | ((path: string) => NodeWebSocket) | null
 
   /**
    * The hostname or ip address of the server.  Default: localhost.
    */
-  host?: string
+  host?: string | null
 
   /**
    * The port to connect to the server on.  Default: 9090.
    */
-  port?: number
+  port?: number | null
 
   /**
    * The name of this client. Usually the app name.
@@ -55,7 +55,7 @@ export interface ClientOptions<Client> extends LifeCycleMethods {
   /**
    * Fires when the server sends a command.
    */
-  onCommand?: (command: any) => void
+  onCommand?: ((command: any) => void) | null
 
   /**
    * Fires when we connect to the server.
diff --git a/lib/reactotron-core-client/src/plugins/benchmark.ts b/lib/reactotron-core-client/src/plugins/benchmark.ts
index 37e71f7aa..4d53bd9ba 100644
--- a/lib/reactotron-core-client/src/plugins/benchmark.ts
+++ b/lib/reactotron-core-client/src/plugins/benchmark.ts
@@ -7,7 +7,7 @@ const benchmark = () => (reactotron: ReactotronCore) => {
   const { startTimer } = reactotron
 
   const benchmark = (title: string) => {
-    const steps = []
+    const steps = [] as Array<{title: string, time: number, delta: number}>
     const elapsed = startTimer()
     const step = (stepTitle: string) => {
       const previousTime = steps.length === 0 ? 0 : (steps[steps.length - 1] as any).time
diff --git a/lib/reactotron-core-client/src/reactotron-core-client.ts b/lib/reactotron-core-client/src/reactotron-core-client.ts
index 755b9ced8..792e197d3 100644
--- a/lib/reactotron-core-client/src/reactotron-core-client.ts
+++ b/lib/reactotron-core-client/src/reactotron-core-client.ts
@@ -101,7 +101,7 @@ export interface ReactotronCore {
     important?: boolean
   ) => void
   display: (config: DisplayConfig) => void
-  onCustomCommand: <Args extends CustomCommandArg[] = CustomCommand["args"]>(
+  onCustomCommand: <Args extends CustomCommandArg[] = Exclude<CustomCommand["args"], undefined>>(
     config: CustomCommand<Args>
   ) => () => void | ((config: string, optHandler?: () => void) => () => void)
   /**
@@ -161,9 +161,11 @@ function emptyPromise() {
   return Promise.resolve("")
 }
 
-export class ReactotronImpl implements ReactotronCore {
+export class ReactotronImpl
+  implements Omit<ReactotronCore, "options" | "plugins" | "configure" | "connect" | "use">
+{
   // the configuration options
-  options: ClientOptions<ReactotronCore>
+  options!: ClientOptions<ReactotronCore>
 
   /**
    * Are we connected to a server?
@@ -173,7 +175,7 @@ export class ReactotronImpl implements ReactotronCore {
   /**
    * The socket we're using.
    */
-  socket: WebSocket = null
+  socket: WebSocket = null as never
 
   /**
    * Available plugins.
@@ -221,7 +223,7 @@ export class ReactotronImpl implements ReactotronCore {
     // options get merged & validated before getting set
     const newOptions = Object.assign(
       {
-        createSocket: null,
+        createSocket: null as never,
         host: "localhost",
         port: 9090,
         name: "reactotron-core-client",
@@ -240,10 +242,11 @@ export class ReactotronImpl implements ReactotronCore {
 
     // if we have plugins, let's add them here
     if (Array.isArray(this.options.plugins)) {
-      this.options.plugins.forEach((p) => this.use(p))
+      this.options.plugins.forEach((p) => this.use(p as never))
     }
 
-    return this as this & InferFeaturesFromPlugins<this, ClientOptions<this>["plugins"]>
+    return this as this &
+      InferFeaturesFromPlugins<this, Exclude<ClientOptions<this>["plugins"], undefined>>
   }
 
   close() {
@@ -270,7 +273,7 @@ export class ReactotronImpl implements ReactotronCore {
 
     // establish a connection to the server
     const protocol = secure ? "wss" : "ws"
-    const socket = createSocket(`${protocol}://${host}:${port}`)
+    const socket = createSocket!(`${protocol}://${host}:${port}`)
 
     // fires when we talk to the server
     const onOpen = () => {
@@ -282,7 +285,7 @@ export class ReactotronImpl implements ReactotronCore {
 
       const getClientIdPromise = getClientId || emptyPromise
 
-      getClientIdPromise(name).then((clientId) => {
+      getClientIdPromise(name!).then((clientId) => {
         this.isReady = true
         // introduce ourselves
         this.send("client.intro", {
@@ -352,7 +355,7 @@ export class ReactotronImpl implements ReactotronCore {
     }
 
     // this is ws style from require('ws') on node js
-    if ("on" in socket && socket.on) {
+    if ("on" in socket && socket.on!) {
       const nodeWebSocket = socket as WebSocket
       nodeWebSocket.on("open", onOpen)
       nodeWebSocket.on("close", onClose)
@@ -461,7 +464,7 @@ export class ReactotronImpl implements ReactotronCore {
       // here's how we're going to inject these in
       const inject = (key: string) => {
         // grab the function
-        const featureFunction = plugin.features[key]
+        const featureFunction = plugin.features![key]
 
         // only functions may pass
         if (typeof featureFunction !== "function") {
@@ -494,20 +497,20 @@ export class ReactotronImpl implements ReactotronCore {
   onCustomCommand(config: CustomCommand | string, optHandler?: () => void): () => void {
     let command: string
     let handler: () => void
-    let title: string
-    let description: string
-    let args: CustomCommandArg[]
+    let title!: string
+    let description!: string
+    let args!: CustomCommandArg[]
 
     if (typeof config === "string") {
       command = config
-      handler = optHandler
+      handler = optHandler!
     } else {
       command = config.command
       handler = config.handler
 
-      title = config.title
-      description = config.description
-      args = config.args
+      title = config.title!
+      description = config.description!
+      args = config.args!
     }
 
     // Validations
@@ -535,7 +538,7 @@ export class ReactotronImpl implements ReactotronCore {
     }
 
     if (args) {
-      const argNames = []
+      const argNames = [] as string[]
 
       args.forEach((arg) => {
         if (!arg.name) {
@@ -592,5 +595,5 @@ export function createClient<Client extends ReactotronCore = ReactotronCore>(
   options?: ClientOptions<Client>
 ) {
   const client = new ReactotronImpl()
-  return client.configure(options as unknown) as unknown as Client
+  return client.configure(options as never) as unknown as Client
 }
diff --git a/lib/reactotron-core-client/src/serialize.ts b/lib/reactotron-core-client/src/serialize.ts
index 9c69c6359..a42280b9f 100644
--- a/lib/reactotron-core-client/src/serialize.ts
+++ b/lib/reactotron-core-client/src/serialize.ts
@@ -49,9 +49,9 @@ function getFunctionName(fn: any): string {
  *
  *  @param {any} source - The victim.
  */
-function serialize(source, proxyHack = false) {
-  const stack = []
-  const keys = []
+function serialize(source: any, proxyHack = false) {
+  const stack = [] as any[]
+  const keys = [] as string[]
 
   /**
    * Replace this object node with something potentially custom.
@@ -60,7 +60,7 @@ function serialize(source, proxyHack = false) {
    * @param {*} value - The value to replace.
    */
   function serializer(replacer) {
-    return function (this: any, key, value) {
+    return function (this: any, key: string, value: any) {
       // slam dunks
       if (value === true) return true
 
diff --git a/lib/reactotron-core-client/src/validate.ts b/lib/reactotron-core-client/src/validate.ts
index c70bc6b15..991542e6e 100644
--- a/lib/reactotron-core-client/src/validate.ts
+++ b/lib/reactotron-core-client/src/validate.ts
@@ -5,7 +5,8 @@ const isCreateSocketValid = (
   createSocket: unknown
 ): createSocket is ClientOptions<ReactotronCore>["createSocket"] =>
   typeof createSocket !== "undefined" && createSocket !== null
-const isHostValid = (host: string): boolean => typeof host === "string" && host && host !== ""
+const isHostValid = (host: string): boolean =>
+  (typeof host === "string" && host && host !== "") as boolean
 const isPortValid = (port: number): boolean =>
   typeof port === "number" && port >= 1 && port <= 65535
 const onCommandValid = (fn: (cmd: string) => any) => typeof fn === "function"
@@ -21,15 +22,15 @@ const validate = (options: ClientOptions<ReactotronCore>) => {
     throw new Error("invalid createSocket function")
   }
 
-  if (!isHostValid(host)) {
+  if (!isHostValid(host!)) {
     throw new Error("invalid host")
   }
 
-  if (!isPortValid(port)) {
+  if (!isPortValid(port!)) {
     throw new Error("invalid port")
   }
 
-  if (!onCommandValid(onCommand)) {
+  if (!onCommandValid(onCommand!)) {
     throw new Error("invalid onCommand handler")
   }
 }
diff --git a/lib/reactotron-core-client/test/configure.test.ts b/lib/reactotron-core-client/test/configure.test.ts
index d134ff52d..e0dd1f2a9 100644
--- a/lib/reactotron-core-client/test/configure.test.ts
+++ b/lib/reactotron-core-client/test/configure.test.ts
@@ -1,5 +1,5 @@
 import { createClient } from "../src/reactotron-core-client"
-import WebSocket from "ws"
+import { WebSocket } from "ws"
 
 const createSocket = (path) => new WebSocket(path)
 
diff --git a/lib/reactotron-core-client/test/plugin-clear.test.ts b/lib/reactotron-core-client/test/plugin-clear.test.ts
index 7f0b59e42..7156b7c3e 100644
--- a/lib/reactotron-core-client/test/plugin-clear.test.ts
+++ b/lib/reactotron-core-client/test/plugin-clear.test.ts
@@ -1,12 +1,12 @@
 import { createClient, corePlugins } from "../src/reactotron-core-client"
 import plugin from "../src/plugins/clear"
-import WebSocket from "ws"
+import { WebSocket } from "ws"
 
 const createSocket = (path) => new WebSocket(path)
 
 test("clears", () => {
   const client: any = createClient({ createSocket })
-  const results = []
+  const results = [] as Array<{ type: string; payload: any }>
   client.send = (type, payload) => results.push({ type, payload })
   client.use(plugin())
   expect(client.plugins.length).toBe(corePlugins.length + 1)
diff --git a/lib/reactotron-core-client/test/plugin-logger.test.ts b/lib/reactotron-core-client/test/plugin-logger.test.ts
index c5f4b0597..5291c4813 100644
--- a/lib/reactotron-core-client/test/plugin-logger.test.ts
+++ b/lib/reactotron-core-client/test/plugin-logger.test.ts
@@ -1,12 +1,12 @@
 import { createClient, corePlugins } from "../src/reactotron-core-client"
 import plugin from "../src/plugins/logger"
-import WebSocket from "ws"
+import { WebSocket } from "ws"
 
 const createSocket = (path) => new WebSocket(path)
 
 test("the 4 functions send the right data", () => {
   const client: any = createClient({ createSocket })
-  const results = []
+  const results = [] as Array<{ type: string; payload: any }>
   client.send = (type, payload) => {
     results.push({ type, payload })
   }
diff --git a/lib/reactotron-core-client/tsconfig.json b/lib/reactotron-core-client/tsconfig.json
index 83f6d142e..46a102175 100644
--- a/lib/reactotron-core-client/tsconfig.json
+++ b/lib/reactotron-core-client/tsconfig.json
@@ -4,6 +4,7 @@
     "allowJs": false,
     "declaration": true,
     "rootDir": ".",
+    "strict": true,
     "declarationDir": "dist/types",
     "emitDeclarationOnly": true,
     "emitDecoratorMetadata": true,
diff --git a/yarn.lock b/yarn.lock
index ae0d1d7e6..888472fa7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -24568,7 +24568,7 @@ __metadata:
     rollup-plugin-resolve: "npm:0.0.1-predev.1"
     ts-jest: "npm:^29.1.1"
     tslib: "npm:^2.6.2"
-    typescript: "npm:^4.9.5"
+    typescript: "npm:^5.1.3"
     ws: "npm:^8.14.2"
   languageName: unknown
   linkType: soft