diff --git a/src/pages/api/erettsegi.ts b/src/pages/api/erettsegi.ts
index 999537d..114f9f7 100644
--- a/src/pages/api/erettsegi.ts
+++ b/src/pages/api/erettsegi.ts
@@ -85,5 +85,6 @@ export default function handler(req: NextApiRequest, res: NextApiResponse) {
       break
   }
 
+  res.setHeader('Cache-Control', 's-maxage=31536000')
   res.status(200).json({ flPdfUrl, utPdfUrl, flZipUrl, utZipUrl })
 }
diff --git a/src/pages/api/proxy.ts b/src/pages/api/proxy.ts
index c4ce2c2..d75e6c7 100644
--- a/src/pages/api/proxy.ts
+++ b/src/pages/api/proxy.ts
@@ -20,6 +20,7 @@ export default async function handler(
   }
 
   try {
+    res.setHeader('Cache-Control', 's-maxage=31536000')
     const response = await fetch(link, { method: 'GET' })
     const contentType = response.headers.get('content-type')
     if (contentType == 'application/pdf') {
diff --git a/src/pages/api/validate.ts b/src/pages/api/validate.ts
index 9c15f42..0b7faec 100644
--- a/src/pages/api/validate.ts
+++ b/src/pages/api/validate.ts
@@ -15,6 +15,7 @@ export default async function handler(
   }
 
   try {
+    res.setHeader('Cache-Control', 's-maxage=31536000')
     const { protocol, host } = new URL(link)
     if (protocol && host) {
       const response = await fetch(link, { method: 'HEAD' })