diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 4e2052883..6d231e87d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -2,7 +2,7 @@
 
 Thank you for considering to contribute to `node-fetch` 💖
 
-Please note that this project is released with a [Contributor Code of Conduct][./CODE_OF_CONDUCT.md].
+Please note that this project is released with a [Contributor Code of Conduct](CODE_OF_CONDUCT.md).
 By participating you agree to abide by its terms.
 
 ## Setup
diff --git a/README.md b/README.md
index 6b27b2a06..37fd608f1 100644
--- a/README.md
+++ b/README.md
@@ -669,7 +669,7 @@ See [options](#fetch-options) for exact meaning of these extensions.
 <small>_(spec-compliant)_</small>
 
 - `input` A string representing a URL, or another `Request` (which will be cloned)
-- `options` [Options][#fetch-options] for the HTTP(S) request
+- `options` [Options](#fetch-options) for the HTTP(S) request
 
 Constructs a new `Request` object. The constructor is identical to that in the [browser](https://developer.mozilla.org/en-US/docs/Web/API/Request/Request).
 
diff --git a/src/request.js b/src/request.js
index a4d1b2209..a63f7e606 100644
--- a/src/request.js
+++ b/src/request.js
@@ -61,7 +61,9 @@ export default class Request extends Body {
 		}
 
 		let method = init.method || input.method || 'GET';
-		method = method.toUpperCase();
+		if (/^(delete|get|head|options|post|put)$/i.test(method)) {
+			method = method.toUpperCase();
+		}
 
 		if ('data' in init) {
 			doBadDataWarn();
diff --git a/test/request.js b/test/request.js
index b8ba107e9..03cbe3cf1 100644
--- a/test/request.js
+++ b/test/request.js
@@ -151,6 +151,24 @@ describe('Request', () => {
 		expect(request.headers.get('a')).to.equal('1');
 	});
 
+	it('should uppercase DELETE, GET, HEAD, OPTIONS, POST and PUT methods', () => {
+		const url = base;
+		for (const method of ['DELETE', 'GET', 'HEAD', 'OPTIONS', 'POST', 'PUT']) {
+			const request = new Request(url, {
+				method: method.toLowerCase()
+			});
+			expect(request.method).to.equal(method);
+		}
+	});
+
+	it('should not uppercase unknown methods and patch', () => {
+		const url = base;
+		for (const method of ['patch', 'chicken']) {
+			const request = new Request(url, {method});
+			expect(request.method).to.equal(method);
+		}
+	});
+
 	it('should support arrayBuffer() method', () => {
 		const url = base;
 		const request = new Request(url, {