diff --git a/docs/type-safety.md b/docs/type-safety.md
index 64e5151..43532dd 100644
--- a/docs/type-safety.md
+++ b/docs/type-safety.md
@@ -14,7 +14,9 @@ export interface TranslationsKeys {
   // Specify here all the namespaces you have...
 }
 
-export interface TranslateFunction<Namespace extends keyof TranslationsKeys>  {
+type TranslationNamespace = keyof TranslationsKeys;
+
+export interface TranslateFunction<Namespace extends TranslationNamespace>  {
   (
     key: TranslationsKeys[Namespace],
     ...rest: Tail<Parameters<Translate>>
@@ -22,20 +24,20 @@ export interface TranslateFunction<Namespace extends keyof TranslationsKeys>  {
   <T extends string>(template: TemplateStringsArray): string
 };
 
-export interface TypeSafeTranslate<Namespace extends keyof TranslationsKeys>
+export interface TypeSafeTranslate<Namespace extends TranslationNamespace>
   extends Omit<I18n, 't'> {
   t: TranslateFunction<Namespace>
 }
 
 declare module 'next-translate/useTranslation' {
   export default function useTranslation<
-    Namespace extends keyof TranslationsKeys
+    Namespace extends TranslationNamespace
   >(namespace: Namespace): TypeSafeTranslate<Namespace>
 }
 
 declare module 'next-translate/getT' {
   export default function getT<
-    Namespace extends keyof TranslationsKeys
+    Namespace extends TranslationNamespace
   >(locale?: string, namespace: Namespace): Promise<TranslateFunction<Namespace>>  
 }
 ```
@@ -46,4 +48,4 @@ Then type safety should work:
 
 <img width="282" alt="Screenshot 2023-07-17 at 19 22 00" src="https://github.com/aralroca/next-translate/assets/13313058/616987b4-e49b-4cf2-b511-cdfaba57e1d2">
 
-Reference: https://github.com/aralroca/next-translate/pull/1108
+Reference: <https://github.com/aralroca/next-translate/pull/1108>