diff --git a/types/three/three-core.d.ts b/types/three/three-core.d.ts
index 639fba5ba5..4866cbfd54 100755
--- a/types/three/three-core.d.ts
+++ b/types/three/three-core.d.ts
@@ -867,6 +867,7 @@ export class BufferGeometry extends EventDispatcher {
     boundingBox: Box3;
     boundingSphere: Sphere;
     drawRange: { start: number, count: number };
+    userData: {[key: string]: any};
 
     getIndex(): BufferAttribute;
     setIndex( index: BufferAttribute|number[] ): void;