diff --git a/package.json b/package.json
index 88f05ebb4a..d37e25e8ac 100644
--- a/package.json
+++ b/package.json
@@ -68,7 +68,7 @@
     "fs-extra": "^10.1.0",
     "globby": "^13.1.2",
     "gzip-size": "^7.0.0",
-    "h3": "^0.8.3",
+    "h3": "^0.8.4",
     "hookable": "^5.4.1",
     "http-proxy": "^1.18.1",
     "is-primitive": "^3.0.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index a0cc521cff..f677bcd5f3 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -49,7 +49,7 @@ importers:
       fs-extra: ^10.1.0
       globby: ^13.1.2
       gzip-size: ^7.0.0
-      h3: ^0.8.3
+      h3: ^0.8.4
       hookable: ^5.4.1
       http-proxy: ^1.18.1
       is-primitive: ^3.0.1
@@ -112,7 +112,7 @@ importers:
       fs-extra: 10.1.0
       globby: 13.1.2
       gzip-size: 7.0.0
-      h3: 0.8.3
+      h3: 0.8.4
       hookable: 5.4.1
       http-proxy: 1.18.1
       is-primitive: 3.0.1
@@ -3163,8 +3163,8 @@ packages:
       duplexer: 0.1.2
     dev: false
 
-  /h3/0.8.3:
-    resolution: {integrity: sha512-SUTWtkopWX04yzF0YGRwccNpvbRheTkib3PdOsjqx2hBhQcrmljMa28K8dXJd6Kn1LhPia8je093hpRdCObBPg==}
+  /h3/0.8.4:
+    resolution: {integrity: sha512-U7ZD/Te+LBS1IpUvsZRe+E+ZiA3zQS0u43DMrZ+raiVObeYe0G5F4Kr/g6Fn2fH92Np0ROkij/wEhkAMbUsBdQ==}
     dependencies:
       cookie-es: 0.5.0
       destr: 1.1.1
@@ -5114,7 +5114,7 @@ packages:
       anymatch: 3.1.2
       chokidar: 3.5.3
       destr: 1.1.1
-      h3: 0.8.3
+      h3: 0.8.4
       ioredis: 5.2.3
       listhen: 0.3.4
       mkdir: 0.0.2
diff --git a/src/runtime/cache.ts b/src/runtime/cache.ts
index 83ece789e4..8765c7d08e 100644
--- a/src/runtime/cache.ts
+++ b/src/runtime/cache.ts
@@ -173,8 +173,8 @@ export function defineCachedEventHandler <T=any> (
 
     // Collect cachable headers
     const headers = event.res.getHeaders()
-    headers.Etag = `W/"${hash(body)}"`
-    headers['Last-Modified'] = new Date().toUTCString()
+    headers.etag = headers.Etag || headers.etag || `W/"${hash(body)}"`
+    headers['last-modified'] = headers['Last-Modified'] || headers['last-modified'] || new Date().toUTCString()
     const cacheControl = []
     if (opts.swr) {
       if (opts.maxAge) {
@@ -189,7 +189,7 @@ export function defineCachedEventHandler <T=any> (
       cacheControl.push(`max-age=${opts.maxAge}`)
     }
     if (cacheControl.length) {
-      headers['Cache-Control'] = cacheControl.join(', ')
+      headers['cache-control'] = cacheControl.join(', ')
     }
 
     // Create cache entry for response
@@ -222,7 +222,7 @@ export function defineCachedEventHandler <T=any> (
 
     // Check for cache headers
     if (handleCacheHeaders(event, {
-      modifiedTime: new Date(response.headers['Last-Modified'] as string),
+      modifiedTime: new Date(response.headers['last-modified'] as string),
       etag: response.headers.etag as string,
       maxAge: opts.maxAge
     })) {