diff --git a/examples/jsm/misc/Volume.d.ts b/examples/jsm/misc/Volume.d.ts
index e048e0411b4d8ab92d17ab124d6629bddc19bd55..dc4f12adbd4ed4b1e541894ebab2647213cea3d1 100644
--- a/examples/jsm/misc/Volume.d.ts
+++ b/examples/jsm/misc/Volume.d.ts
@@ -5,7 +5,7 @@ import {
 import { VolumeSlice } from "./VolumeSlice.js";
 
 export class Volume {
-  constructor( xLength?: number, yLength?: number, zLength?: number, type?:string, arrayBuffer: ArrayLike<number> );
+  constructor( xLength?: number, yLength?: number, zLength?: number, type?:string, arrayBuffer?: ArrayLike<number> );
 
   xLength: number;
   yLength: number;
@@ -27,7 +27,7 @@ export class Volume {
   access( i: number, j: number, k: number ): number;
   reverseAccess( index: number ): number[];
 
-  map( functionToMap: function, context: this ): this;
+  map( functionToMap: Function, context: this ): this;
 
   extractPerpendicularPlane ( axis: string, RASIndex: number ): object;
   extractSlice( axis: string, index: number ): VolumeSlice;
diff --git a/examples/jsm/misc/VolumeSlice.d.ts b/examples/jsm/misc/VolumeSlice.d.ts
index 197b70a5080546a6efc82cc59044c087e83d8842..5e88fd13f51641354857621568ab8d8cad489cab 100644
--- a/examples/jsm/misc/VolumeSlice.d.ts
+++ b/examples/jsm/misc/VolumeSlice.d.ts
@@ -3,7 +3,7 @@ import {
   Mesh,
 } from '../../../src/Three';
 
-import { volume } from './Volume';
+import { Volume } from './Volume';
 
 export class VolumeSlice {
   constructor( volume: Volume, index?: number, axis?: string );