diff --git a/types/builtin-components.d.ts b/types/builtin-components.d.ts
index b5484c4..7c98c5f 100644
--- a/types/builtin-components.d.ts
+++ b/types/builtin-components.d.ts
@@ -28,6 +28,7 @@ export interface TransitionPropsBase {
 
 export interface TransitionProps extends TransitionPropsBase {
   mode?: string;
+  duration?: number | { enter: number; leave: number };
 }
 
 export interface TransitionGroupProps extends TransitionPropsBase {