diff --git a/src/utils/cx.ts b/src/utils/cx.ts
index 27adb15..7f44544 100644
--- a/src/utils/cx.ts
+++ b/src/utils/cx.ts
@@ -1,7 +1,7 @@
 /**
  * cx('class1', { class2: true, class3: false }) --> 'class1 class2'
  */
-export default function cx(...classNames: (string | object)[]): string {
+export default function cx(...classNames: any[]): string {
   return classNames
     .filter(Boolean)
     .map(className => {
@@ -10,7 +10,7 @@ export default function cx(...classNames: (string | object)[]): string {
           return className
         case 'object':
           return cx(
-            ...Object.entries(className).map(([key, value]) => (Boolean(value) ? key : null))
+            ...Object.entries(className).map(([key, value]) => (Boolean(value) ? key : null)),
           )
         default:
           return ''
diff --git a/src/utils/storageHelper.ts b/src/utils/storageHelper.ts
index 9635c1b..0b67a72 100644
--- a/src/utils/storageHelper.ts
+++ b/src/utils/storageHelper.ts
@@ -1,10 +1,10 @@
 const localStorage = chrome.storage.local
 
-function get(mapping: string | string[] | object) {
+function get(mapping: string | string[] | object): Promise<any> {
   return new Promise(resolve => localStorage.get(mapping, resolve))
 }
 
-function set(value: any) {
+function set(value: any): Promise<void> {
   // it's ok
   return new Promise(resolve => localStorage.set(value, resolve))
 }