diff --git a/index.d.ts b/index.d.ts
index ef3d9bfb6..c7b08b21f 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -330,8 +330,11 @@ export interface IDeriveLinkedEntriesConfig {
    *  locale one of the locales in the space being transformed
    *
    * The return value must be an object with the same keys as specified in derivedFields. Their values will be written to the respective new entry fields for the current locale (i.e. {nameField: 'myNewValue'})
-  */
-  deriveEntryForLocale: (inputFields: ContentFields, locale: string) => { [field: string]: any }
+   */
+  deriveEntryForLocale: (
+    inputFields: ContentFields,
+    locale: string
+  ) => { [field: string]: any } | undefined,
 }
 
 /**