diff --git a/app/javascript/packs/application.ts b/app/javascript/packs/application.ts
index 364cae3c46..1087b1c4cb 100644
--- a/app/javascript/packs/application.ts
+++ b/app/javascript/packs/application.ts
@@ -10,6 +10,6 @@ start();
 loadPolyfills()
   .then(loadLocale)
   .then(main)
-  .catch((e) => {
+  .catch((e: unknown) => {
     console.error(e);
   });
diff --git a/app/javascript/packs/error.ts b/app/javascript/packs/error.ts
index ddc7655dd4..db68484f3a 100644
--- a/app/javascript/packs/error.ts
+++ b/app/javascript/packs/error.ts
@@ -13,6 +13,6 @@ ready(() => {
   image.addEventListener('mouseleave', () => {
     image.src = '/oops.png';
   });
-}).catch((e) => {
+}).catch((e: unknown) => {
   console.error(e);
 });
diff --git a/app/javascript/packs/share.tsx b/app/javascript/packs/share.tsx
index c68fc8fe86..5070bff6ea 100644
--- a/app/javascript/packs/share.tsx
+++ b/app/javascript/packs/share.tsx
@@ -24,13 +24,13 @@ function loaded() {
 }
 
 function main() {
-  ready(loaded).catch((error) => {
+  ready(loaded).catch((error: unknown) => {
     throw error;
   });
 }
 
 loadPolyfills()
   .then(main)
-  .catch((error) => {
+  .catch((error: unknown) => {
     throw error;
   });
diff --git a/app/javascript/packs/sign_up.ts b/app/javascript/packs/sign_up.ts
index 70d7c7aef3..880738fcb7 100644
--- a/app/javascript/packs/sign_up.ts
+++ b/app/javascript/packs/sign_up.ts
@@ -43,6 +43,6 @@ ready(() => {
 
       button.appendChild(container);
     });
-}).catch((e) => {
+}).catch((e: unknown) => {
   throw e;
 });