diff --git a/index.d.ts b/index.d.ts
index 9de94f752..7ad186cc5 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -37,7 +37,7 @@ declare module 'i18next' {
   // interface i18n {
   //   reportNamespaces?: ReportNamespaces;
   // }
-  interface CustomInstanceExtenstions {
+  interface CustomInstanceExtensions {
     reportNamespaces?: ReportNamespaces;
   }
 }