diff --git a/bin/server.js b/bin/server.js
index 579438b..7bde87b 100755
--- a/bin/server.js
+++ b/bin/server.js
@@ -32,12 +32,23 @@ function devMapper(file, type, data) {
 	}
 }
 
-const STATIC_MAX_AGE = 10 * 60; // 10 minutes
-const RENDER_MAX_AGE = 60 * 60 * 24 * 7; // 1 week
+const STATIC_CACHE = {
+	maxAgeSeconds: 10 * 60, // 10 minutes
+	staleSeconds: 60 * 60 * 24 * 365, // 1 year
+};
+const RENDER_CACHE = {
+	immutable: true,
+	maxAgeSeconds: 60 * 60 * 24 * 30, // 1 month
+	staleSeconds: 60 * 60 * 24 * 365, // 1 year
+};
+const PREVIEW_CACHE = {
+	maxAgeSeconds: 60 * 60, // 1 hour
+	staleSeconds: 60 * 60 * 24, // 1 day
+};
 const SKETCH_CSS_SHA = 'sha256-s7UPtBgvov5WNF9C1DlTZDpqwLgEmfiWha5a5p/Zn7E=';
 
 const statics = new StaticRequestHandler('')
-	.setCacheMaxAge(DEV ? 0 : STATIC_MAX_AGE)
+	.setCache(DEV ? {} : STATIC_CACHE)
 	.addHeader('Content-Security-Policy', [
 		'base-uri \'self\'',
 		'default-src \'none\'',
@@ -86,7 +97,7 @@ if(DEV) {
 }
 
 const render = new RenderRequestHandler('/render')
-	.setCacheMaxAge(DEV ? 0 : RENDER_MAX_AGE)
+	.setCache(DEV ? {} : RENDER_CACHE)
 	.setCrossOrigin(true)
 	.addHeader('Content-Security-Policy', [
 		'base-uri \'self\'',
@@ -99,7 +110,7 @@ const render = new RenderRequestHandler('/render')
 	.addHeader('X-Content-Type-Options', 'nosniff');
 
 const preview = new PreviewRequestHandler('/preview')
-	.setCacheMaxAge(DEV ? 0 : RENDER_MAX_AGE)
+	.setCache(DEV ? {} : PREVIEW_CACHE)
 	.addHeader('Content-Security-Policy', [
 		'base-uri \'self\'',
 		'default-src \'none\'',
diff --git a/bin/server/RequestHandler.js b/bin/server/RequestHandler.js
index c0714bd..82c5d34 100644
--- a/bin/server/RequestHandler.js
+++ b/bin/server/RequestHandler.js
@@ -4,13 +4,17 @@ class RequestHandler {
 		this.matcher = matcher;
 		this.handleFn = handleFn;
 		this.cacheMaxAge = 0;
+		this.cacheStale = 0;
+		this.immutable = false;
 		this.allowAllOrigins = false;
 		this.staticHeaders = [];
 		this.info = `Custom handler at ${this.method} ${this.matcher}`;
 	}
 
-	setCacheMaxAge(seconds) {
-		this.cacheMaxAge = seconds;
+	setCache({ maxAgeSeconds = 0, staleSeconds = 0, immutable = false }) {
+		this.cacheMaxAge = maxAgeSeconds;
+		this.cacheStale = staleSeconds;
+		this.immutable = immutable;
 		return this;
 	}
 
@@ -31,7 +35,9 @@ class RequestHandler {
 		if(this.cacheMaxAge > 0) {
 			res.setHeader(
 				'Cache-Control',
-				`public, max-age=${this.cacheMaxAge}`
+				`public, max-age=${this.cacheMaxAge}` +
+				(this.cacheStale ? `, stale-if-error=${this.cacheStale}` : '') +
+				(this.immutable ? ', immutable' : '')
 			);
 		}
 		for(const header of this.staticHeaders) {