diff --git a/src/postprocessing/AfterimagePass.js b/src/postprocessing/AfterimagePass.js
deleted file mode 100644
index 33561f6a..00000000
--- a/src/postprocessing/AfterimagePass.js
+++ /dev/null
@@ -1,84 +0,0 @@
-import {
-  LinearFilter,
-  MeshBasicMaterial,
-  NearestFilter,
-  RGBAFormat,
-  ShaderMaterial,
-  UniformsUtils,
-  WebGLRenderTarget,
-} from 'three'
-import { Pass, FullScreenQuad } from '../postprocessing/Pass'
-import { AfterimageShader } from '../shaders/AfterimageShader'
-
-var AfterimagePass = function (damp) {
-  Pass.call(this)
-
-  if (AfterimageShader === undefined) console.error('THREE.AfterimagePass relies on AfterimageShader')
-
-  this.shader = AfterimageShader
-
-  this.uniforms = UniformsUtils.clone(this.shader.uniforms)
-
-  this.uniforms['damp'].value = damp !== undefined ? damp : 0.96
-
-  this.textureComp = new WebGLRenderTarget(window.innerWidth, window.innerHeight, {
-    minFilter: LinearFilter,
-    magFilter: NearestFilter,
-    format: RGBAFormat,
-  })
-
-  this.textureOld = new WebGLRenderTarget(window.innerWidth, window.innerHeight, {
-    minFilter: LinearFilter,
-    magFilter: NearestFilter,
-    format: RGBAFormat,
-  })
-
-  this.shaderMaterial = new ShaderMaterial({
-    uniforms: this.uniforms,
-    vertexShader: this.shader.vertexShader,
-    fragmentShader: this.shader.fragmentShader,
-  })
-
-  this.compFsQuad = new FullScreenQuad(this.shaderMaterial)
-
-  var material = new MeshBasicMaterial()
-  this.copyFsQuad = new FullScreenQuad(material)
-}
-
-AfterimagePass.prototype = Object.assign(Object.create(Pass.prototype), {
-  constructor: AfterimagePass,
-
-  render: function (renderer, writeBuffer, readBuffer) {
-    this.uniforms['tOld'].value = this.textureOld.texture
-    this.uniforms['tNew'].value = readBuffer.texture
-
-    renderer.setRenderTarget(this.textureComp)
-    this.compFsQuad.render(renderer)
-
-    this.copyFsQuad.material.map = this.textureComp.texture
-
-    if (this.renderToScreen) {
-      renderer.setRenderTarget(null)
-      this.copyFsQuad.render(renderer)
-    } else {
-      renderer.setRenderTarget(writeBuffer)
-
-      if (this.clear) renderer.clear()
-
-      this.copyFsQuad.render(renderer)
-    }
-
-    // Swap buffers.
-    var temp = this.textureOld
-    this.textureOld = this.textureComp
-    this.textureComp = temp
-    // Now textureOld contains the latest image, ready for the next frame.
-  },
-
-  setSize: function (width, height) {
-    this.textureComp.setSize(width, height)
-    this.textureOld.setSize(width, height)
-  },
-})
-
-export { AfterimagePass }
diff --git a/src/postprocessing/AfterimagePass.ts b/src/postprocessing/AfterimagePass.ts
new file mode 100644
index 00000000..89346c64
--- /dev/null
+++ b/src/postprocessing/AfterimagePass.ts
@@ -0,0 +1,87 @@
+import {
+  LinearFilter,
+  MeshBasicMaterial,
+  NearestFilter,
+  RGBAFormat,
+  WebGLRenderer,
+  ShaderMaterial,
+  UniformsUtils,
+  WebGLRenderTarget,
+} from 'three'
+import { Pass, FullScreenQuad } from './Pass'
+import { AfterimageShader } from '../shaders/AfterimageShader'
+
+class AfterimagePass extends Pass {
+  public shader
+  public uniforms
+  public textureComp: WebGLRenderTarget
+  public textureOld: WebGLRenderTarget
+  public shaderMaterial: ShaderMaterial
+  public compFsQuad: FullScreenQuad<ShaderMaterial>
+  public copyFsQuad: FullScreenQuad<MeshBasicMaterial>
+
+  constructor(damp = 0.96, shader = AfterimageShader) {
+    super()
+
+    this.shader = shader
+    this.uniforms = UniformsUtils.clone(shader.uniforms)
+    this.uniforms['damp'].value = damp
+
+    this.textureComp = new WebGLRenderTarget(window.innerWidth, window.innerHeight, {
+      minFilter: LinearFilter,
+      magFilter: NearestFilter,
+      format: RGBAFormat,
+    })
+
+    this.textureOld = new WebGLRenderTarget(window.innerWidth, window.innerHeight, {
+      minFilter: LinearFilter,
+      magFilter: NearestFilter,
+      format: RGBAFormat,
+    })
+
+    this.shaderMaterial = new ShaderMaterial({
+      uniforms: this.uniforms,
+      vertexShader: this.shader.vertexShader,
+      fragmentShader: this.shader.fragmentShader,
+    })
+
+    this.compFsQuad = new FullScreenQuad(this.shaderMaterial)
+
+    let material = new MeshBasicMaterial()
+    this.copyFsQuad = new FullScreenQuad(material)
+  }
+
+  public render(renderer: WebGLRenderer, writeBuffer: WebGLRenderTarget, readBuffer: WebGLRenderTarget): void {
+    this.uniforms['tOld'].value = this.textureOld.texture
+    this.uniforms['tNew'].value = readBuffer.texture
+
+    renderer.setRenderTarget(this.textureComp)
+    this.compFsQuad.render(renderer)
+
+    this.copyFsQuad.material.map = this.textureComp.texture
+
+    if (this.renderToScreen) {
+      renderer.setRenderTarget(null)
+      this.copyFsQuad.render(renderer)
+    } else {
+      renderer.setRenderTarget(writeBuffer)
+
+      if (this.clear) renderer.clear()
+
+      this.copyFsQuad.render(renderer)
+    }
+
+    // Swap buffers.
+    let temp = this.textureOld
+    this.textureOld = this.textureComp
+    this.textureComp = temp
+    // Now textureOld contains the latest image, ready for the next frame.
+  }
+
+  public setSize(width: number, height: number): void {
+    this.textureComp.setSize(width, height)
+    this.textureOld.setSize(width, height)
+  }
+}
+
+export { AfterimagePass }
diff --git a/src/shaders/AfterimageShader.js b/src/shaders/AfterimageShader.ts
similarity index 97%
rename from src/shaders/AfterimageShader.js
rename to src/shaders/AfterimageShader.ts
index 223ef041..63457e54 100644
--- a/src/shaders/AfterimageShader.js
+++ b/src/shaders/AfterimageShader.ts
@@ -4,7 +4,7 @@
  * https://codepen.io/brunoimbrizi/pen/MoRJaN?page=1&
  */
 
-var AfterimageShader = {
+const AfterimageShader = {
   uniforms: {
     damp: { value: 0.96 },
     tOld: { value: null },