diff --git a/src/background/index.ts b/src/background/index.ts
index 25b1908..8570400 100644
--- a/src/background/index.ts
+++ b/src/background/index.ts
@@ -1,13 +1,13 @@
 chrome.runtime.onInstalled.addListener(async () => {
-  for (const cs of chrome.runtime.getManifest().content_scripts) {
-    for (const tab of await chrome.tabs.query({ url: cs.matches })) {
+  for (const cs of chrome.runtime.getManifest().content_scripts ?? []) {
+    for (const tab of await chrome.tabs.query({ url: cs.matches ?? [] })) {
       chrome.scripting.executeScript({
-        target: { tabId: tab.id },
-        files: cs.js,
+        target: { tabId: tab.id ?? 0 },
+        files: cs.js ?? [],
       })
       cs.css?.forEach(css => {
         chrome.scripting.insertCSS({
-          target: { tabId: tab.id },
+          target: { tabId: tab.id ?? 0 },
           files: [css],
         })
       })
diff --git a/src/content/components/Trigger.tsx b/src/content/components/Trigger.tsx
index 6df51ae..f4f9e13 100644
--- a/src/content/components/Trigger.tsx
+++ b/src/content/components/Trigger.tsx
@@ -7,12 +7,21 @@ import { MainModal } from './MainModal'
 import { useShadowRoot } from '@/hooks/useShadowRoot'
 import { useShortcutStore } from '@/storage/useShortcutStore'
 import { useStorageStore } from '@/storage/useStorageStore'
+import type { StorageData } from '@/types'
 
 const isActiveElementEditable = (element: Element | null): boolean => {
   return element instanceof HTMLInputElement || element instanceof HTMLTextAreaElement
 }
 
-const TriggerButton = ({ isOpen, onClick, settings }) => (
+const TriggerButton = ({
+  isOpen,
+  onClick,
+  settings,
+}: {
+  isOpen: boolean
+  onClick: () => void
+  settings: StorageData['settings']
+}) => (
   <div
     onClick={onClick}
     className="d-mask d-mask-squircle fixed bottom-25px right-25px h-56px w-56px cursor-pointer bg-cover bg-center bg-no-repeat shadow-lg transition-all duration-300 ease-in-out hover:shadow-xl"
@@ -50,7 +59,7 @@ export function Trigger() {
 
   const handleHotkey = () => {
     const activeElement = shadowRoot?.activeElement
-    if (isEditing || isActiveElementEditable(activeElement)) {
+    if (isEditing || isActiveElementEditable(activeElement ?? null)) {
       return
     }
 
diff --git a/src/content/components/setting/Shortcut.tsx b/src/content/components/setting/Shortcut.tsx
index 4f3d01b..667e34d 100644
--- a/src/content/components/setting/Shortcut.tsx
+++ b/src/content/components/setting/Shortcut.tsx
@@ -42,8 +42,8 @@ export function Shortcut() {
     if (key.length === 1 || ['F1', 'F2', 'F3', 'F4', 'F5', 'F6', 'F7', 'F8', 'F9', 'F10', 'F11', 'F12'].includes(key)) {
       let processedKey = key.toLowerCase()
 
-      if (KOREAN_TO_ENGLISH[processedKey]) {
-        processedKey = KOREAN_TO_ENGLISH[processedKey]
+      if (KOREAN_TO_ENGLISH[processedKey as keyof typeof KOREAN_TO_ENGLISH]) {
+        processedKey = KOREAN_TO_ENGLISH[processedKey as keyof typeof KOREAN_TO_ENGLISH]
       }
 
       const newShortcut = [
diff --git a/src/content/components/task/TaskCard.tsx b/src/content/components/task/TaskCard.tsx
index 4b7ee11..baf548c 100644
--- a/src/content/components/task/TaskCard.tsx
+++ b/src/content/components/task/TaskCard.tsx
@@ -5,7 +5,7 @@ import { Video, FileText, CheckCircle, AlertTriangle, Clock, XCircle } from 'luc
 import type { Activity } from '@/types'
 import { cn } from '@/utils/cn'
 
-const StatusBadge = ({ isExpired, hasSubmitted }) => {
+const StatusBadge = ({ isExpired, hasSubmitted }: { isExpired: boolean; hasSubmitted: boolean }) => {
   if (isExpired && !hasSubmitted) {
     return (
       <span className="flex items-center text-12px text-red-600">
diff --git a/src/context/themeContext.ts b/src/context/themeContext.ts
index 696c278..da5c865 100644
--- a/src/context/themeContext.ts
+++ b/src/context/themeContext.ts
@@ -7,7 +7,7 @@ type ThemeContextValue<T = Theme> = {
   setTheme: (theme: T) => void
 }
 
-export const ThemeContext = createContext<ThemeContextValue>(null)
+export const ThemeContext = createContext<ThemeContextValue | null>(null)
 
 export const useThemeContext = () => {
   const context = useContext(ThemeContext)
diff --git a/src/utils/cheerioUtils.ts b/src/utils/cheerioUtils.ts
index d4e23b4..79f7ffa 100644
--- a/src/utils/cheerioUtils.ts
+++ b/src/utils/cheerioUtils.ts
@@ -9,4 +9,4 @@ export const mapElement = <T>(elements: Cheerio<AnyNode>, callback: (i: number,
 }
 
 export const getText = ($el: Cheerio<AnyNode>): string => $el.text().trim()
-export const getAttr = ($el: Cheerio<AnyNode>, attr: string): string => $el.attr(attr) || ''
+export const getAttr = ($el: Cheerio<AnyNode>, attr: string): string | undefined => $el.attr(attr)
diff --git a/src/utils/getLinkId.ts b/src/utils/getLinkId.ts
index f34986c..79dedf5 100644
--- a/src/utils/getLinkId.ts
+++ b/src/utils/getLinkId.ts
@@ -1,4 +1,11 @@
-export function getLinkId(link: string) {
-  if (!link) return ''
-  return new URL(link).searchParams.get('id')
+export function getLinkId(link?: string) {
+  if (link == null) {
+    return ''
+  }
+
+  try {
+    return new URL(link).searchParams.get('id') ?? ''
+  } catch {
+    return ''
+  }
 }