diff --git a/types/react-beautiful-dnd/index.d.ts b/types/react-beautiful-dnd/index.d.ts
index d02c86bbcf..8d25e79407 100644
--- a/types/react-beautiful-dnd/index.d.ts
+++ b/types/react-beautiful-dnd/index.d.ts
@@ -12,7 +12,7 @@ export type Id = string;
 export type DraggableId = Id;
 export type DroppableId = Id;
 export type TypeId = Id;
-export type ZIndex = number | string;
+export type ZIndex = React.CSSProperties['zIndex'];
 export type DropReason = 'DROP' | 'CANCEL';
 export type Announce = (message: string) => void;