diff --git a/src/loaders/AnimationLoader.js b/src/loaders/AnimationLoader.js
index eeee815b8d581d..661dab954034cd 100644
--- a/src/loaders/AnimationLoader.js
+++ b/src/loaders/AnimationLoader.js
@@ -2,24 +2,22 @@ import { AnimationClip } from '../animation/AnimationClip.js';
 import { FileLoader } from './FileLoader.js';
 import { Loader } from './Loader.js';
 
-function AnimationLoader( manager ) {
+class AnimationLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-AnimationLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: AnimationLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		const scope = this;
 
-		const loader = new FileLoader( scope.manager );
-		loader.setPath( scope.path );
-		loader.setRequestHeader( scope.requestHeader );
-		loader.setWithCredentials( scope.withCredentials );
+		const loader = new FileLoader( this.manager );
+		loader.setPath( this.path );
+		loader.setRequestHeader( this.requestHeader );
+		loader.setWithCredentials( this.withCredentials );
 		loader.load( url, function ( text ) {
 
 			try {
@@ -44,9 +42,9 @@ AnimationLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 		}, onProgress, onError );
 
-	},
+	}
 
-	parse: function ( json ) {
+	parse( json ) {
 
 		const animations = [];
 
@@ -62,7 +60,7 @@ AnimationLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 	}
 
-} );
+}
 
 
 export { AnimationLoader };
diff --git a/src/loaders/AudioLoader.js b/src/loaders/AudioLoader.js
index 68ba89177f3754..857394e4812f71 100644
--- a/src/loaders/AudioLoader.js
+++ b/src/loaders/AudioLoader.js
@@ -2,25 +2,23 @@ import { AudioContext } from '../audio/AudioContext.js';
 import { FileLoader } from './FileLoader.js';
 import { Loader } from './Loader.js';
 
-function AudioLoader( manager ) {
+class AudioLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-AudioLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: AudioLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		const scope = this;
 
-		const loader = new FileLoader( scope.manager );
+		const loader = new FileLoader( this.manager );
 		loader.setResponseType( 'arraybuffer' );
-		loader.setPath( scope.path );
-		loader.setRequestHeader( scope.requestHeader );
-		loader.setWithCredentials( scope.withCredentials );
+		loader.setPath( this.path );
+		loader.setRequestHeader( this.requestHeader );
+		loader.setWithCredentials( this.withCredentials );
 		loader.load( url, function ( buffer ) {
 
 			try {
@@ -56,7 +54,7 @@ AudioLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 	}
 
-} );
+}
 
 
 export { AudioLoader };
diff --git a/src/loaders/BufferGeometryLoader.js b/src/loaders/BufferGeometryLoader.js
index de11fd0595e1a3..7ed96a3673dc70 100644
--- a/src/loaders/BufferGeometryLoader.js
+++ b/src/loaders/BufferGeometryLoader.js
@@ -9,17 +9,15 @@ import { InstancedBufferAttribute } from '../core/InstancedBufferAttribute.js';
 import { InterleavedBufferAttribute } from '../core/InterleavedBufferAttribute.js';
 import { InterleavedBuffer } from '../core/InterleavedBuffer.js';
 
-function BufferGeometryLoader( manager ) {
+class BufferGeometryLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-BufferGeometryLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: BufferGeometryLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		const scope = this;
 
@@ -51,9 +49,9 @@ BufferGeometryLoader.prototype = Object.assign( Object.create( Loader.prototype
 
 		}, onProgress, onError );
 
-	},
+	}
 
-	parse: function ( json ) {
+	parse( json ) {
 
 		const interleavedBufferMap = {};
 		const arrayBufferMap = {};
@@ -211,7 +209,7 @@ BufferGeometryLoader.prototype = Object.assign( Object.create( Loader.prototype
 
 	}
 
-} );
+}
 
 const TYPED_ARRAYS = {
 	Int8Array: Int8Array,
diff --git a/src/loaders/CubeTextureLoader.js b/src/loaders/CubeTextureLoader.js
index 61a508d3f71d10..2e784a221e8d27 100644
--- a/src/loaders/CubeTextureLoader.js
+++ b/src/loaders/CubeTextureLoader.js
@@ -2,17 +2,15 @@ import { ImageLoader } from './ImageLoader.js';
 import { CubeTexture } from '../textures/CubeTexture.js';
 import { Loader } from './Loader.js';
 
-function CubeTextureLoader( manager ) {
+class CubeTextureLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-CubeTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: CubeTextureLoader,
+	}
 
-	load: function ( urls, onLoad, onProgress, onError ) {
+	load( urls, onLoad, onProgress, onError ) {
 
 		const texture = new CubeTexture();
 
@@ -52,7 +50,7 @@ CubeTextureLoader.prototype = Object.assign( Object.create( Loader.prototype ),
 
 	}
 
-} );
+}
 
 
 export { CubeTextureLoader };
diff --git a/src/loaders/FontLoader.js b/src/loaders/FontLoader.js
index 3122f5964b1fc2..986b5adc1cf1ee 100644
--- a/src/loaders/FontLoader.js
+++ b/src/loaders/FontLoader.js
@@ -2,17 +2,15 @@ import { Font } from '../extras/core/Font.js';
 import { FileLoader } from './FileLoader.js';
 import { Loader } from './Loader.js';
 
-function FontLoader( manager ) {
+class FontLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-FontLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: FontLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		const scope = this;
 
@@ -41,15 +39,15 @@ FontLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 		}, onProgress, onError );
 
-	},
+	}
 
-	parse: function ( json ) {
+	parse( json ) {
 
 		return new Font( json );
 
 	}
 
-} );
+}
 
 
 export { FontLoader };
diff --git a/src/loaders/ImageLoader.js b/src/loaders/ImageLoader.js
index 2f8278931e7074..6a7eaaf01adf2b 100644
--- a/src/loaders/ImageLoader.js
+++ b/src/loaders/ImageLoader.js
@@ -1,17 +1,15 @@
 import { Cache } from './Cache.js';
 import { Loader } from './Loader.js';
 
-function ImageLoader( manager ) {
+class ImageLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-}
-
-ImageLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
+		super( manager );
 
-	constructor: ImageLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		if ( this.path !== undefined ) url = this.path + url;
 
@@ -81,7 +79,7 @@ ImageLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 	}
 
-} );
+}
 
 
 export { ImageLoader };
diff --git a/src/loaders/MaterialLoader.js b/src/loaders/MaterialLoader.js
index 25ae862e663024..9014e8bbc508ce 100644
--- a/src/loaders/MaterialLoader.js
+++ b/src/loaders/MaterialLoader.js
@@ -8,19 +8,16 @@ import { FileLoader } from './FileLoader.js';
 import { Loader } from './Loader.js';
 import * as Materials from '../materials/Materials.js';
 
-function MaterialLoader( manager ) {
+class MaterialLoader extends Loader {
 
-	Loader.call( this, manager );
+	constructor( manager ) {
 
-	this.textures = {};
+		super( manager );
+		this.textures = {};
 
-}
-
-MaterialLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
-
-	constructor: MaterialLoader,
+	}
 
-	load: function ( url, onLoad, onProgress, onError ) {
+	load( url, onLoad, onProgress, onError ) {
 
 		const scope = this;
 
@@ -52,9 +49,9 @@ MaterialLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 		}, onProgress, onError );
 
-	},
+	}
 
-	parse: function ( json ) {
+	parse( json ) {
 
 		const textures = this.textures;
 
@@ -283,16 +280,16 @@ MaterialLoader.prototype = Object.assign( Object.create( Loader.prototype ), {
 
 		return material;
 
-	},
+	}
 
-	setTextures: function ( value ) {
+	setTextures( value ) {
 
 		this.textures = value;
 		return this;
 
 	}
 
-} );
+}
 
 
 export { MaterialLoader };