diff --git a/API.md b/API.md
index ff3cd5e..ed75d3b 100644
--- a/API.md
+++ b/API.md
@@ -1,6 +1,6 @@
 # API
 
+Routes marked with 🔒 need authentification.
+
 [Books](/API_Books)
 
-
-
diff --git a/API_Books.md b/API_Books.md
index f8f2ca5..b61e9e9 100644
--- a/API_Books.md
+++ b/API_Books.md
@@ -40,7 +40,7 @@ Search for a book which title contains "test":
 
 **GET**`/api/v1/books/search?s=test`
 
-### PUT** **`/books`
+### PUT** **`/books` 🔒
 
 Creates a new book.