diff --git a/spec/suites/SpecHelper.js b/spec/suites/SpecHelper.js
index 939a6faaf..1c610e00c 100644
--- a/spec/suites/SpecHelper.js
+++ b/spec/suites/SpecHelper.js
@@ -16,16 +16,17 @@ expect.Assertion.prototype.nearLatLng = function (expected, delta) {
 		.be.within(expected.lng - delta, expected.lng + delta);
 };
 
-happen.at = function (what, x, y, props) {
-	this.once(document.elementFromPoint(x, y), L.Util.extend({
+happen.at = function (what, x, y, props = {}) {
+	this.once(document.elementFromPoint(x, y), {
 		type: what,
 		clientX: x,
 		clientY: y,
 		screenX: x,
 		screenY: y,
 		which: 1,
-		button: 0
-	}, props || {}));
+		button: 0,
+		...props
+	});
 };
 
 happen.makeEvent = (function (makeEvent) {
diff --git a/spec/suites/core/UtilSpec.js b/spec/suites/core/UtilSpec.js
index b73678c5a..394c08823 100644
--- a/spec/suites/core/UtilSpec.js
+++ b/spec/suites/core/UtilSpec.js
@@ -1,38 +1,4 @@
 describe('Util', () => {
-	describe('#extend', () => {
-		let a;
-
-		beforeEach(() => {
-			a = {
-				foo: 5,
-				bar: 'asd'
-			};
-		});
-
-		it('extends the first argument with the properties of the second', () => {
-			L.Util.extend(a, {
-				bar: 7,
-				baz: 3
-			});
-
-			expect(a).to.eql({
-				foo: 5,
-				bar: 7,
-				baz: 3
-			});
-		});
-
-		it('accepts more than 2 arguments', () => {
-			L.Util.extend(a, {bar: 7}, {baz: 3});
-
-			expect(a).to.eql({
-				foo: 5,
-				bar: 7,
-				baz: 3
-			});
-		});
-	});
-
 	describe('#stamp', () => {
 		it('sets a unique id on the given object and returns it', () => {
 			const a = {},
diff --git a/spec/suites/dom/DomEvent.DoubleTapSpec.js b/spec/suites/dom/DomEvent.DoubleTapSpec.js
index f6efbffef..02be5b920 100644
--- a/spec/suites/dom/DomEvent.DoubleTapSpec.js
+++ b/spec/suites/dom/DomEvent.DoubleTapSpec.js
@@ -76,7 +76,7 @@ describe('DomEvent.DoubleTapSpec.js', () => {
 		happen.click(container, click);
 
 		const event = spy.lastCall.args[0];
-		const expectedProps = L.extend(click, {
+		const expectedProps = Object.assign(click, {
 			type: 'dblclick',
 			// bubbles: true,    // not important, as we do not actually dispatch the event
 			// cancelable: true, //
diff --git a/spec/suites/dom/DomEvent.PointerSpec.js b/spec/suites/dom/DomEvent.PointerSpec.js
index c3fe8d23d..81bbae470 100644
--- a/spec/suites/dom/DomEvent.PointerSpec.js
+++ b/spec/suites/dom/DomEvent.PointerSpec.js
@@ -99,7 +99,7 @@ describe('DomEvent.Pointer', () => {
 
 			// pointerdown/touchstart
 			const pointer1 = {clientX:1, clientY:1, pointerId: 1};
-			happen.once(el, L.extend({type: 'pointerdown'}, pointer1));
+			happen.once(el, {type: 'pointerdown', ...pointer1}));
 			let evt = listeners.touchstart.lastCall.args[0];
 			expect(evt.type).to.be('pointerdown');
 			expect(evt).to.have.keys('touches', 'changedTouches');
@@ -110,7 +110,7 @@ describe('DomEvent.Pointer', () => {
 
 			// another pointerdown/touchstart (multitouch)
 			const pointer2 = {clientX:2, clientY:2, pointerId: 2};
-			happen.once(el, L.extend({type: 'pointerdown'}, pointer2));
+			happen.once(el, {type: 'pointerdown', ...pointer2});
 			evt = listeners.touchstart.lastCall.args[0];
 			expect(evt.type).to.be('pointerdown');
 			expect(evt).to.have.keys('touches', 'changedTouches');
@@ -120,8 +120,8 @@ describe('DomEvent.Pointer', () => {
 			expect(containIn([pointer1, pointer2], evt.touches)).to.be.ok();
 
 			// pointermove/touchmove (multitouch)
-			L.extend(pointer1, {clientX:11, clientY:11});
-			happen.once(el, L.extend({type: 'pointermove'}, pointer1));
+			Object.assign(pointer1, {clientX:11, clientY:11});
+			happen.once(el, {type: 'pointermove', ...pointer1});
 			evt = listeners.touchmove.lastCall.args[0];
 			expect(evt.type).to.be('pointermove');
 			expect(evt).to.have.keys('touches', 'changedTouches');
@@ -131,7 +131,7 @@ describe('DomEvent.Pointer', () => {
 			expect(containIn([pointer1, pointer2], evt.touches)).to.be.ok();
 
 			// pointerup/touchend (multitouch)
-			happen.once(el, L.extend({type: 'pointerup'}, pointer2));
+			happen.once(el, {type: 'pointerup', ...pointer2});
 			evt = listeners.touchend.lastCall.args[0];
 			expect(evt.type).to.be('pointerup');
 			expect(evt).to.have.keys('touches', 'changedTouches');
@@ -141,7 +141,7 @@ describe('DomEvent.Pointer', () => {
 			expect(containIn(pointer1, evt.touches[0])).to.be.ok();
 
 			// pointercancel/touchcancel
-			happen.once(el, L.extend({type: 'pointercancel'}, pointer1));
+			happen.once(el, {type: 'pointercancel', ...pointer1});
 			evt = listeners.touchcancel.lastCall.args[0];
 			expect(evt.type).to.be('pointercancel');
 			expect(evt).to.have.keys('touches', 'changedTouches');
diff --git a/src/core/Class.js b/src/core/Class.js
index 01c060be9..6a2a30498 100644
--- a/src/core/Class.js
+++ b/src/core/Class.js
@@ -44,23 +44,23 @@ Class.extend = function (props) {
 
 	// mix static properties into the class
 	if (props.statics) {
-		Util.extend(NewClass, props.statics);
+		Object.assign(NewClass, props.statics);
 	}
 
 	// mix includes into the prototype
 	if (props.includes) {
-		Util.extend.apply(null, [proto].concat(props.includes));
+		Object.assign(proto, ...props.includes);
 	}
 
 	// mix given properties into the prototype
-	Util.extend(proto, props);
+	Object.assign(proto, props);
 	delete proto.statics;
 	delete proto.includes;
 
 	// merge options
 	if (proto.options) {
 		proto.options = parentProto.options ? Util.create(parentProto.options) : {};
-		Util.extend(proto.options, props.options);
+		Object.assign(proto.options, props.options);
 	}
 
 	proto._initHooks = [];
@@ -89,7 +89,7 @@ Class.extend = function (props) {
 // [Includes a mixin](#class-includes) into the current class.
 Class.include = function (props) {
 	const parentOptions = this.prototype.options;
-	Util.extend(this.prototype, props);
+	Object.assign(this.prototype, props);
 	if (props.options) {
 		this.prototype.options = parentOptions;
 		this.mergeOptions(props.options);
@@ -100,7 +100,7 @@ Class.include = function (props) {
 // @function mergeOptions(options: Object): this
 // [Merges `options`](#class-options) into the defaults of the class.
 Class.mergeOptions = function (options) {
-	Util.extend(this.prototype.options, options);
+	Object.assign(this.prototype.options, options);
 	return this;
 };
 
diff --git a/src/core/Events.js b/src/core/Events.js
index 7366aa504..04e76a392 100644
--- a/src/core/Events.js
+++ b/src/core/Events.js
@@ -175,11 +175,12 @@ export const Events = {
 	fire(type, data, propagate) {
 		if (!this.listens(type, propagate)) { return this; }
 
-		const event = Util.extend({}, data, {
+		const event = {
+			...data,
 			type,
 			target: this,
 			sourceTarget: data && data.sourceTarget || this
-		});
+		};
 
 		if (this._events) {
 			const listeners = this._events[type];
@@ -308,10 +309,11 @@ export const Events = {
 
 	_propagateEvent(e) {
 		for (const id in this._eventParents) {
-			this._eventParents[id].fire(e.type, Util.extend({
+			this._eventParents[id].fire(e.type, {
 				layer: e.target,
-				propagatedFrom: e.target
-			}, e), true);
+				propagatedFrom: e.target,
+				...e
+			}, true);
 		}
 	}
 };
diff --git a/src/core/Util.js b/src/core/Util.js
index 5e03d5f00..8df5cb374 100644
--- a/src/core/Util.js
+++ b/src/core/Util.js
@@ -4,20 +4,6 @@
  * Various utility functions, used by Leaflet internally.
  */
 
-// @function extend(dest: Object, src?: Object): Object
-// Merges the properties of the `src` object (or multiple objects) into `dest` object and returns the latter. Has an `L.extend` shortcut.
-export function extend(dest, ...args) {
-	let i, j, len, src;
-
-	for (j = 0, len = args.length; j < len; j++) {
-		src = args[j];
-		for (i in src) {
-			dest[i] = src[i];
-		}
-	}
-	return dest;
-}
-
 // @function create(proto: Object, properties?: Object): Object
 // Compatibility polyfill for [Object.create](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/create)
 export const create = Object.create || (function () {
diff --git a/src/core/index.js b/src/core/index.js
index d493c37cd..c8407b652 100644
--- a/src/core/index.js
+++ b/src/core/index.js
@@ -5,4 +5,4 @@ export {Handler} from './Handler';
 
 import * as Util from './Util';
 export {Util};
-export {extend, stamp, setOptions} from './Util';
+export {stamp, setOptions} from './Util';
diff --git a/src/geo/crs/CRS.EPSG3395.js b/src/geo/crs/CRS.EPSG3395.js
index 595625d86..1537af560 100644
--- a/src/geo/crs/CRS.EPSG3395.js
+++ b/src/geo/crs/CRS.EPSG3395.js
@@ -1,7 +1,6 @@
 import {Earth} from './CRS.Earth';
 import {Mercator} from '../projection/Projection.Mercator';
 import {toTransformation} from '../../geometry/Transformation';
-import * as Util from '../../core/Util';
 
 /*
  * @namespace CRS
@@ -9,7 +8,8 @@ import * as Util from '../../core/Util';
  *
  * Rarely used by some commercial tile providers. Uses Elliptical Mercator projection.
  */
-export const EPSG3395 = Util.extend({}, Earth, {
+export const EPSG3395 = {
+	...Earth,
 	code: 'EPSG:3395',
 	projection: Mercator,
 
@@ -17,4 +17,4 @@ export const EPSG3395 = Util.extend({}, Earth, {
 		const scale = 0.5 / (Math.PI * Mercator.R);
 		return toTransformation(scale, 0.5, -scale, 0.5);
 	}())
-});
+};
diff --git a/src/geo/crs/CRS.EPSG3857.js b/src/geo/crs/CRS.EPSG3857.js
index 0b6a7aaca..9905dee05 100644
--- a/src/geo/crs/CRS.EPSG3857.js
+++ b/src/geo/crs/CRS.EPSG3857.js
@@ -1,7 +1,6 @@
 import {Earth} from './CRS.Earth';
 import {SphericalMercator} from '../projection/Projection.SphericalMercator';
 import {toTransformation} from '../../geometry/Transformation';
-import * as Util from '../../core/Util';
 
 /*
  * @namespace CRS
@@ -12,7 +11,8 @@ import * as Util from '../../core/Util';
  * Map's `crs` option.
  */
 
-export const EPSG3857 = Util.extend({}, Earth, {
+export const EPSG3857 = {
+	...Earth,
 	code: 'EPSG:3857',
 	projection: SphericalMercator,
 
@@ -20,8 +20,9 @@ export const EPSG3857 = Util.extend({}, Earth, {
 		const scale = 0.5 / (Math.PI * SphericalMercator.R);
 		return toTransformation(scale, 0.5, -scale, 0.5);
 	}())
-});
+};
 
-export const EPSG900913 = Util.extend({}, EPSG3857, {
+export const EPSG900913 =  {
+	...EPSG3857,
 	code: 'EPSG:900913'
-});
+};
diff --git a/src/geo/crs/CRS.EPSG4326.js b/src/geo/crs/CRS.EPSG4326.js
index 5922791c7..57a77aaf7 100644
--- a/src/geo/crs/CRS.EPSG4326.js
+++ b/src/geo/crs/CRS.EPSG4326.js
@@ -1,7 +1,6 @@
 import {Earth} from './CRS.Earth';
 import {LonLat} from '../projection/Projection.LonLat';
 import {toTransformation} from '../../geometry/Transformation';
-import * as Util from '../../core/Util';
 
 /*
  * @namespace CRS
@@ -16,8 +15,9 @@ import * as Util from '../../core/Util';
  * or (-180,-90) for `TileLayer`s with [the `tms` option](#tilelayer-tms) set.
  */
 
-export const EPSG4326 = Util.extend({}, Earth, {
+export const EPSG4326 = {
+	...Earth,
 	code: 'EPSG:4326',
 	projection: LonLat,
 	transformation: toTransformation(1 / 180, 1, -1 / 180, 0.5)
-});
+};
diff --git a/src/geo/crs/CRS.Earth.js b/src/geo/crs/CRS.Earth.js
index 8af0f3932..cf937c654 100755
--- a/src/geo/crs/CRS.Earth.js
+++ b/src/geo/crs/CRS.Earth.js
@@ -1,5 +1,4 @@
 import {CRS} from './CRS';
-import * as Util from '../../core/Util';
 
 /*
  * @namespace CRS
@@ -11,7 +10,8 @@ import * as Util from '../../core/Util';
  * meters.
  */
 
-export const Earth = Util.extend({}, CRS, {
+export const Earth = {
+	...CRS,
 	wrapLng: [-180, 180],
 
 	// Mean Earth Radius, as recommended for use by
@@ -30,4 +30,4 @@ export const Earth = Util.extend({}, CRS, {
 		    c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
 		return this.R * c;
 	}
-});
+};
diff --git a/src/geo/crs/CRS.Simple.js b/src/geo/crs/CRS.Simple.js
index 61818b016..43043abfa 100644
--- a/src/geo/crs/CRS.Simple.js
+++ b/src/geo/crs/CRS.Simple.js
@@ -1,7 +1,6 @@
 import {CRS} from './CRS';
 import {LonLat} from '../projection/Projection.LonLat';
 import {toTransformation} from '../../geometry/Transformation';
-import * as Util from '../../core/Util';
 
 /*
  * @namespace CRS
@@ -13,7 +12,8 @@ import * as Util from '../../core/Util';
  * simple euclidean distance.
  */
 
-export const Simple = Util.extend({}, CRS, {
+export const Simple = {
+	...CRS,
 	projection: LonLat,
 	transformation: toTransformation(1, 0, -1, 0),
 
@@ -33,4 +33,4 @@ export const Simple = Util.extend({}, CRS, {
 	},
 
 	infinite: true
-});
+};
diff --git a/src/layer/GeoJSON.js b/src/layer/GeoJSON.js
index cb3ffa364..0570891ac 100644
--- a/src/layer/GeoJSON.js
+++ b/src/layer/GeoJSON.js
@@ -138,7 +138,7 @@ export const GeoJSON = FeatureGroup.extend({
 			return this.eachLayer(this.resetStyle, this);
 		}
 		// reset any custom styles
-		layer.options = Util.extend({}, layer.defaultOptions);
+		layer.options = {...layer.defaultOptions};
 		this._setLayerStyle(layer, this.options.style);
 		return this;
 	},
@@ -296,7 +296,7 @@ export function latLngsToCoords(latlngs, levelsDeep, closed, precision) {
 
 export function getFeature(layer, newGeometry) {
 	return layer.feature ?
-		Util.extend({}, layer.feature, {geometry: newGeometry}) :
+		{...layer.feature, geometry: newGeometry} :
 		asFeature(newGeometry);
 }
 
diff --git a/src/layer/tile/TileLayer.WMS.js b/src/layer/tile/TileLayer.WMS.js
index 770684da6..f345866e3 100644
--- a/src/layer/tile/TileLayer.WMS.js
+++ b/src/layer/tile/TileLayer.WMS.js
@@ -1,5 +1,5 @@
 import {TileLayer} from './TileLayer';
-import {extend, setOptions, getParamString} from '../../core/Util';
+import {setOptions, getParamString} from '../../core/Util';
 import Browser from '../../core/Browser';
 import {EPSG4326} from '../../geo/crs/CRS.EPSG4326';
 import {toBounds} from '../../geometry/Bounds';
@@ -69,7 +69,7 @@ export const TileLayerWMS = TileLayer.extend({
 
 		this._url = url;
 
-		const wmsParams = extend({}, this.defaultWmsParams);
+		const wmsParams = {...this.defaultWmsParams};
 
 		// all keys that are not TileLayer options go to WMS params
 		for (const i in options) {
@@ -119,7 +119,7 @@ export const TileLayerWMS = TileLayer.extend({
 	// Merges an object with the new parameters and re-requests tiles on the current screen (unless `noRedraw` was set to true).
 	setParams(params, noRedraw) {
 
-		extend(this.wmsParams, params);
+		Object.assign(this.wmsParams, params);
 
 		if (!noRedraw) {
 			this.redraw();
diff --git a/src/layer/tile/TileLayer.js b/src/layer/tile/TileLayer.js
index 5cda7ce3c..be4f59435 100644
--- a/src/layer/tile/TileLayer.js
+++ b/src/layer/tile/TileLayer.js
@@ -193,7 +193,7 @@ export const TileLayer = GridLayer.extend({
 			data['-y'] = invertedY;
 		}
 
-		return Util.template(this._url, Util.extend(data, this.options));
+		return Util.template(this._url, Object.assign(data, this.options));
 	},
 
 	_tileOnLoad(done, tile) {
diff --git a/src/layer/vector/Circle.js b/src/layer/vector/Circle.js
index ca5f5715d..3cdb61209 100644
--- a/src/layer/vector/Circle.js
+++ b/src/layer/vector/Circle.js
@@ -27,7 +27,7 @@ export const Circle = CircleMarker.extend({
 	initialize(latlng, options, legacyOptions) {
 		if (typeof options === 'number') {
 			// Backwards compatibility with 0.7.x factory (latlng, radius, options?)
-			options = Util.extend({}, legacyOptions, {radius: options});
+			options = {...legacyOptions, radius: options};
 		}
 		Util.setOptions(this, options);
 		this._latlng = toLatLng(latlng);
diff --git a/src/map/Map.js b/src/map/Map.js
index f9f1c7ae8..7f1f21720 100644
--- a/src/map/Map.js
+++ b/src/map/Map.js
@@ -182,8 +182,8 @@ export const Map = Evented.extend({
 		if (this._loaded && !options.reset && options !== true) {
 
 			if (options.animate !== undefined) {
-				options.zoom = Util.extend({animate: options.animate}, options.zoom);
-				options.pan = Util.extend({animate: options.animate, duration: options.duration}, options.pan);
+				options.zoom = {animate: options.animate, ...options.zoom};
+				options.pan = {animate: options.animate, duration: options.duration, ...options.pan};
 			}
 
 			// try animating pan or zoom
@@ -553,7 +553,7 @@ export const Map = Evented.extend({
 	invalidateSize(options) {
 		if (!this._loaded) { return this; }
 
-		options = Util.extend({
+		options = Object.assign({
 			animate: false,
 			pan: true
 		}, options === true ? {animate: true} : options);
@@ -618,14 +618,15 @@ export const Map = Evented.extend({
 	// See `Locate options` for more details.
 	locate(options) {
 
-		options = this._locateOptions = Util.extend({
+		options = this._locateOptions = {
 			timeout: 10000,
-			watch: false
+			watch: false,
 			// setView: false
 			// maxZoom: <Number>
 			// maximumAge: 0
 			// enableHighAccuracy: false
-		}, options);
+			...options
+		};
 
 		if (!('geolocation' in navigator)) {
 			this._handleGeolocationError({
@@ -1413,7 +1414,7 @@ export const Map = Evented.extend({
 			// Fired before mouse click on the map (sometimes useful when you
 			// want something to happen on click before any existing click
 			// handlers start running).
-			const synth = Util.extend({}, e);
+			const synth = {...e};
 			synth.type = 'preclick';
 			this._fireDOMEvent(synth, synth.type, canvasTargets);
 		}