diff --git a/test/decentralised_book_index/metadata/author_test.exs b/test/decentralised_book_index/metadata/author_test.exs
index 7ce58ad..233c88c 100644
--- a/test/decentralised_book_index/metadata/author_test.exs
+++ b/test/decentralised_book_index/metadata/author_test.exs
@@ -3,6 +3,9 @@ defmodule DecentralisedBookIndex.Metadata.AuthorTest do
 
   alias DecentralisedBookIndex.Metadata
 
+  alias DecentralisedBookIndex.TestEndpoints
+  @test_server_endpoint TestEndpoints.test_api_endpoint()
+
   setup do
     user = generate(user(role: :moderator))
     %{user: user}
@@ -129,6 +132,17 @@ defmodule DecentralisedBookIndex.Metadata.AuthorTest do
     end
   end
 
+  describe "author and DBIServer relationship" do
+    test "assign a DBIServer", %{user: user} do
+      server = generate(dbi_server(url: @test_server_endpoint))
+
+      assert {:ok, author} =
+               Metadata.create_author("Author", "An description", nil, nil, actor: user)
+      assert {:ok, author} = Metadata.assign_author_dbi_server(author, server.id, actor: user)
+      assert author.dbi_server_id == server.id
+    end
+  end
+
   describe "calculate a brief description" do
     test "a short description is already enough" do
       description = "Amazing!"
diff --git a/test/decentralised_book_index/metadata/book_test.exs b/test/decentralised_book_index/metadata/book_test.exs
index 26037e0..969e029 100644
--- a/test/decentralised_book_index/metadata/book_test.exs
+++ b/test/decentralised_book_index/metadata/book_test.exs
@@ -3,6 +3,9 @@ defmodule DecentralisedBookIndex.Metadata.BookTest do
 
   alias DecentralisedBookIndex.Metadata
 
+  alias DecentralisedBookIndex.TestEndpoints
+  @test_server_endpoint TestEndpoints.test_api_endpoint()
+
   setup do
     user = generate(user(role: :moderator))
     %{user: user}
@@ -274,6 +277,16 @@ defmodule DecentralisedBookIndex.Metadata.BookTest do
     end
   end
 
+  describe "book and DBIServer relationship" do
+    test "assign a DBIServer", %{user: user} do
+      server = generate(dbi_server(url: @test_server_endpoint))
+      book = generate(book())
+
+      assert {:ok, book} = Metadata.assign_book_dbi_server(book, server.id, actor: user)
+      assert book.dbi_server_id == server.id
+    end
+  end
+
   describe "calculate a brief description" do
     test "a short description is already enough" do
       description = "Amazing!"