diff --git a/lodash/index.d.ts b/lodash/index.d.ts
index e1074a4c97..f8b14bb3af 100644
--- a/lodash/index.d.ts
+++ b/lodash/index.d.ts
@@ -10986,7 +10986,7 @@ declare module _ {
          * @param value The value to inspect.
          * @return Returns the cast array.
          */
-        castArray<T>(value: T): T[];
+        castArray<T>(value?: T | T[]): T[];
     }
 
     interface LoDashImplicitWrapper<T> {