diff --git a/types/plugin/duration.d.ts b/types/plugin/duration.d.ts
index 755a219c9..a7e733fe2 100644
--- a/types/plugin/duration.d.ts
+++ b/types/plugin/duration.d.ts
@@ -6,6 +6,15 @@ export as namespace plugin;
 export = plugin
 
 declare namespace plugin {
+  /**
+   * @deprecated Please use more strict types
+   */
+  type DurationInputType = string | number | object
+  /**
+   * @deprecated Please use more strict types
+   */
+  type DurationAddType = number | object | Duration
+  
   type DurationUnitsObjectType = Partial<{
     [unit in Exclude<UnitTypeLongPlural, "dates"> | "weeks"]: number
   }>;
@@ -76,4 +85,4 @@ declare module 'dayjs' {
    */
   export const duration: plugin.CreateDurationType;
   export function isDuration(d: any): d is plugin.Duration
-}
+}
\ No newline at end of file