diff --git a/types/plotly.js/index.d.ts b/types/plotly.js/index.d.ts
index 854960025d..39ecb64d37 100644
--- a/types/plotly.js/index.d.ts
+++ b/types/plotly.js/index.d.ts
@@ -355,7 +355,7 @@ export interface ModeBarButton {
 
 // Data
 
-export type Datum = string | number | Date;
+export type Datum = string | number | Date | null;
 export type TypedArray = Int8Array | Uint8Array | Int16Array | Uint16Array | Int32Array | Uint32Array | Uint8ClampedArray | Float32Array | Float64Array;
 
 export type Dash = 'solid' | 'dot' | 'dash' | 'longdash' | 'dashdot' | 'longdashdot';