diff --git a/src/emit.ts b/src/emit.ts
index 25df51459..df2239cfc 100644
--- a/src/emit.ts
+++ b/src/emit.ts
@@ -1,4 +1,5 @@
 import { setDevtoolsHook, devtools, ComponentPublicInstance } from 'vue'
+import { ComponentInternalInstance } from '@vue/runtime-core'
 
 const enum DevtoolsHooks {
   COMPONENT_EMIT = 'component:emit'
@@ -10,19 +11,17 @@ let events: Record<string, typeof componentEvents>
 export function emitted<T = unknown>(
   vm: ComponentPublicInstance,
   eventName?: string
-): T[] | Record<string, T[]> {
+): undefined | T[] | Record<string, T[]> {
   const cid = vm.$.uid
 
   const vmEvents = (events as Record<string, Record<string, T[]>>)[cid] || {}
   if (eventName) {
-    const emitted = vmEvents
-      ? (vmEvents as Record<string, T[]>)[eventName]
-      : undefined
-    return emitted
+    return vmEvents ? (vmEvents as Record<string, T[]>)[eventName] : undefined
   }
 
   return vmEvents as Record<string, T[]>
 }
+type Events = { [id: number]: Record<string, any> }
 
 export const attachEmitListener = () => {
   events = {}
@@ -30,23 +29,26 @@ export const attachEmitListener = () => {
   setDevtoolsHook(createDevTools(events))
 }
 
-function createDevTools(events): any {
-  const devTools: Partial<typeof devtools> = {
+function createDevTools(events: Events): any {
+  return {
     emit(eventType, ...payload) {
       if (eventType !== DevtoolsHooks.COMPONENT_EMIT) return
 
       const [rootVM, componentVM, event, eventArgs] = payload
       recordEvent(events, componentVM, event, eventArgs)
     }
-  }
-
-  return devTools
+  } as Partial<typeof devtools>
 }
 
-function recordEvent(events, vm, event, args): void {
+function recordEvent(
+  events: Events,
+  vm: ComponentInternalInstance,
+  event: string,
+  args: Events[number]
+): void {
   // Functional component wrapper creates a parent component
   let wrapperVm = vm
-  while (typeof wrapperVm.type === 'function') wrapperVm = wrapperVm.parent
+  while (typeof wrapperVm?.type === 'function') wrapperVm = wrapperVm.parent!
 
   const cid = wrapperVm.uid
   if (!(cid in events)) {
diff --git a/src/mount.ts b/src/mount.ts
index 3e850c30c..38872b59f 100644
--- a/src/mount.ts
+++ b/src/mount.ts
@@ -2,7 +2,6 @@ import {
   h,
   createApp,
   defineComponent,
-  VNodeNormalizedChildren,
   reactive,
   FunctionalComponent,
   ComponentPublicInstance,
@@ -230,7 +229,7 @@ export function mount(
   options?: MountingOptions<any>
 ): VueWrapper<any> {
   // normalise the incoming component
-  let component
+  let component: DefineComponent
 
   if (isFunctionalComponent(originalComponent)) {
     component = defineComponent({
@@ -261,7 +260,7 @@ export function mount(
   }
 
   // handle any slots passed via mounting options
-  const slots: VNodeNormalizedChildren =
+  const slots =
     options?.slots &&
     Object.entries(options.slots).reduce(
       (
@@ -270,7 +269,7 @@ export function mount(
       ): { [key: string]: Function } => {
         // case of an SFC getting passed
         if (typeof slot === 'object' && 'render' in slot) {
-          acc[name] = slot.render
+          acc[name] = slot.render!
           return acc
         }
 
diff --git a/src/vueWrapper.ts b/src/vueWrapper.ts
index 732d1c0c4..94d8c846e 100644
--- a/src/vueWrapper.ts
+++ b/src/vueWrapper.ts
@@ -74,9 +74,11 @@ export class VueWrapper<T extends ComponentPublicInstance> {
     return true
   }
 
-  emitted<T = unknown>(): Record<string, T[]>
-  emitted<T = unknown>(eventName?: string): T[]
-  emitted<T = unknown>(eventName?: string): T[] | Record<string, T[]> {
+  emitted<T = unknown>(): undefined | Record<string, T[]>
+  emitted<T = unknown>(eventName?: string): undefined | T[]
+  emitted<T = unknown>(
+    eventName?: string
+  ): undefined | T[] | Record<string, T[]> {
     return emitted(this.vm, eventName)
   }