diff --git a/source/normalize-arguments.js b/source/normalize-arguments.js
index bf5ba52c3..7614e6b15 100644
--- a/source/normalize-arguments.js
+++ b/source/normalize-arguments.js
@@ -1,5 +1,7 @@
 'use strict';
+/* istanbul ignore next: compatibility reason */
 const URLGlobal = typeof URL === 'undefined' ? require('url').URL : URL; // TODO: Use the `URL` global when targeting Node.js 10
+/* istanbul ignore next: compatibility reason */
 const URLSearchParamsGlobal = typeof URLSearchParams === 'undefined' ? require('url').URLSearchParams : URLSearchParams;
 const is = require('@sindresorhus/is');
 const toReadableStream = require('to-readable-stream');
diff --git a/source/progress.js b/source/progress.js
index cf1821f74..5253925c0 100644
--- a/source/progress.js
+++ b/source/progress.js
@@ -28,16 +28,18 @@ module.exports = {
 		request.once('socket', socket => {
 			const onSocketConnect = () => {
 				progressInterval = setInterval(() => {
+					/* istanbul ignore next: hard to test */
 					if (socket.destroyed) {
 						clearInterval(progressInterval);
 						return;
 					}
 
 					const lastUploaded = uploaded;
+					/* istanbul ignore next: see #490 (occurs randomly!) */
 					const headersSize = request._header ? Buffer.byteLength(request._header) : 0;
 					uploaded = socket.bytesWritten - headersSize;
 
-					// Prevent the known issue of `bytesWritten` being larger than body size
+					/* istanbul ignore next: see https://github.com/sindresorhus/got/pull/322#pullrequestreview-51647813 (no proof) */
 					if (uploadBodySize && uploaded > uploadBodySize) {
 						uploaded = uploadBodySize;
 					}
diff --git a/source/request-as-event-emitter.js b/source/request-as-event-emitter.js
index ace016dd7..c8454d36d 100644
--- a/source/request-as-event-emitter.js
+++ b/source/request-as-event-emitter.js
@@ -1,8 +1,9 @@
 'use strict';
+/* istanbul ignore next: compatibility reason */
+const URLGlobal = typeof URL === 'undefined' ? require('url').URL : URL; // TODO: Use the `URL` global when targeting Node.js 10
 const EventEmitter = require('events');
 const http = require('http');
 const https = require('https');
-const URLGlobal = typeof URL === 'undefined' ? require('url').URL : URL; // TODO: Use the `URL` global when targeting Node.js 10
 const urlLib = require('url');
 const CacheableRequest = require('cacheable-request');
 const is = require('@sindresorhus/is');
@@ -38,6 +39,7 @@ module.exports = options => {
 			options.agent = agents[protocolName] || options.agent;
 		}
 
+		/* istanbul ignore next: electron.net is broken */
 		if (options.useElectronNet && process.versions.electron) {
 			const electron = global['require']('electron'); // eslint-disable-line dot-notation
 			fn = electron.net || electron.remote.net;
diff --git a/source/timed-out.js b/source/timed-out.js
index 1b5e4aa20..89847c9da 100644
--- a/source/timed-out.js
+++ b/source/timed-out.js
@@ -12,8 +12,8 @@ function addTimeout(delay, callback, ...args) {
 	const timeout = setTimeout(
 		() => {
 			immediate = setImmediate(callback, delay, ...args);
+			/* istanbul ignore next: added in node v9.7.0 */
 			if (immediate.unref) {
-				// Added in node v9.7.0
 				immediate.unref();
 			}
 		},
@@ -27,6 +27,7 @@ function addTimeout(delay, callback, ...args) {
 }
 
 module.exports = (request, options) => {
+	/* istanbul ignore next: this makes sure timed-out isn't called twice */
 	if (request[reentry]) {
 		return;
 	}
@@ -68,6 +69,7 @@ module.exports = (request, options) => {
 
 	if (delays.lookup !== undefined && !request.socketPath && !net.isIP(hostname || host)) {
 		request.once('socket', socket => {
+			/* istanbul ignore next: hard to test */
 			if (socket.connecting) {
 				const cancelTimeout = addTimeout(
 					delays.lookup,
@@ -82,6 +84,7 @@ module.exports = (request, options) => {
 
 	if (delays.connect !== undefined) {
 		request.once('socket', socket => {
+			/* istanbul ignore next: hard to test */
 			if (socket.connecting) {
 				const timeConnect = () => {
 					const cancelTimeout = addTimeout(
@@ -106,6 +109,7 @@ module.exports = (request, options) => {
 
 	if (delays.secureConnect !== undefined && options.protocol === 'https:') {
 		request.once('socket', socket => {
+			/* istanbul ignore next: hard to test */
 			if (socket.connecting) {
 				socket.once('connect', () => {
 					const cancelTimeout = addTimeout(
@@ -131,7 +135,7 @@ module.exports = (request, options) => {
 				cancelers.push(cancelTimeout);
 				return cancelTimeout;
 			};
-
+			/* istanbul ignore next: hard to test */
 			if (socket.connecting) {
 				socket.once('connect', () => {
 					request.once('upload-complete', timeRequest());
diff --git a/test/stream.js b/test/stream.js
index 6e38f921d..293d477ef 100644
--- a/test/stream.js
+++ b/test/stream.js
@@ -127,9 +127,10 @@ test('proxying headers works', async t => {
 
 	await server.listen(server.port);
 
-	const {headers} = await got(server.url);
+	const {headers, body} = await got(server.url);
 	t.is(headers.unicorn, 'rainbow');
 	t.is(headers['content-encoding'], undefined);
+	t.is(body, 'ok');
 
 	await server.close();
 });
@@ -164,3 +165,19 @@ test('throws when trying to proxy through a closed stream', async t => {
 	await got(server.url);
 	await server.close();
 });
+
+test('proxies content-encoding header when options.decompress is false', async t => {
+	const server = await createServer();
+
+	server.on('/', (request, response) => {
+		got.stream(s.url, {decompress: false}).pipe(response);
+	});
+
+	await server.listen(server.port);
+
+	const {headers} = await got(server.url);
+	t.is(headers.unicorn, 'rainbow');
+	t.is(headers['content-encoding'], 'gzip');
+
+	await server.close();
+});