diff --git a/documentation/advanced-creation.md b/documentation/advanced-creation.md
index 482db6900..0f90cc82b 100644
--- a/documentation/advanced-creation.md
+++ b/documentation/advanced-creation.md
@@ -66,7 +66,7 @@ const limitDownloadUpload = got.extend({
 ```js
 const noUserAgent = got.extend({
 	headers: {
-		'user-agent': null
+		'user-agent': undefined
 	}
 });
 ```
@@ -117,7 +117,7 @@ const merged = got.extend(controlRedirects, limitDownloadUpload, httpbin, signRe
 	 */
 
 	const MEGABYTE = 1048576;
-	await merged('http://ipv4.download.thinkbroadband.com/5MB.zip', {downloadLimit: MEGABYTE, prefixUrl: ''});
+	await merged('https://ipv4.download.thinkbroadband.com/5MB.zip', {downloadLimit: MEGABYTE, prefixUrl: ''});
 	// CancelError: Exceeded the download limit of 1048576 bytes
 
 	await merged('https://jigsaw.w3.org/HTTP/300/301.html', {allowedHosts: ['google.com'], prefixUrl: ''});
diff --git a/readme.md b/readme.md
index 9dc5241d2..da7e4528a 100644
--- a/readme.md
+++ b/readme.md
@@ -1321,7 +1321,7 @@ stream.destroy();
 <a name="cache-adapters"></a>
 ## Cache
 
-Got implements [RFC 7234](http://httpwg.org/specs/rfc7234.html) compliant HTTP caching which works out of the box in-memory and is easily pluggable with a wide range of storage adapters. Fresh cache entries are served directly from the cache, and stale cache entries are revalidated with `If-None-Match`/`If-Modified-Since` headers. You can read more about the underlying cache behavior in the [`cacheable-request` documentation](https://github.com/lukechilds/cacheable-request). For DNS cache, Got uses [`cacheable-lookup`](https://github.com/szmarczak/cacheable-lookup).
+Got implements [RFC 7234](https://httpwg.org/specs/rfc7234.html) compliant HTTP caching which works out of the box in-memory and is easily pluggable with a wide range of storage adapters. Fresh cache entries are served directly from the cache, and stale cache entries are revalidated with `If-None-Match`/`If-Modified-Since` headers. You can read more about the underlying cache behavior in the [`cacheable-request` documentation](https://github.com/lukechilds/cacheable-request). For DNS cache, Got uses [`cacheable-lookup`](https://github.com/szmarczak/cacheable-lookup).
 
 You can use the JavaScript `Map` type as an in-memory cache: