diff --git a/js/index.ts b/js/index.ts
index 10fae3b..822d6d2 100644
--- a/js/index.ts
+++ b/js/index.ts
@@ -866,6 +866,8 @@ export class PMTiles {
 					d_l = entry.length;
 				}
 			} else {
+				// TODO: We should in fact return a valid RangeResponse
+				// with empty data, but filled in cache control / expires headers
 				return undefined;
 			}
 		}
diff --git a/serverless/aws/src/index.ts b/serverless/aws/src/index.ts
index 163ba0b..05403ed 100644
--- a/serverless/aws/src/index.ts
+++ b/serverless/aws/src/index.ts
@@ -100,7 +100,12 @@ class S3Source implements Source {
 
 		const arr = await resp.Body!.transformToByteArray();
 
-		return { data: arr.buffer };
+		return {
+			data: arr.buffer,
+			etag: resp.ETag,
+			expires: resp.Expires?.toISOString(),
+			cacheControl: resp.CacheControl,
+		};
 	}
 }
 
@@ -156,7 +161,7 @@ export const handler = async (
 	// TODO: metadata and TileJSON
 
 	if (process.env.CORS) {
-		headers['Access-Control-Allow-Origin'] = process.env.CORS;
+		headers["Access-Control-Allow-Origin"] = process.env.CORS;
 	}
 
 	const source = new S3Source(name);
diff --git a/serverless/cloudflare/src/index.ts b/serverless/cloudflare/src/index.ts
index 0144bfe..e3b26a4 100644
--- a/serverless/cloudflare/src/index.ts
+++ b/serverless/cloudflare/src/index.ts
@@ -109,7 +109,12 @@ class R2Source implements Source {
 		}
 		const o = resp as R2ObjectBody;
 		const a = await o.arrayBuffer();
-		return { data: a, etag: o.etag };
+		return {
+			data: a,
+			etag: o.etag,
+			cacheControl: o.httpMetadata?.cacheControl,
+			expires: o.httpMetadata?.cacheExpiry?.toISOString(),
+		};
 	}
 }