diff --git a/lib/rex.rb b/lib/rex.rb
index 777e527..a127952 100644
--- a/lib/rex.rb
+++ b/lib/rex.rb
@@ -1,11 +1,7 @@
 # frozen_string_literal: true
 
 require_relative "rex/version"
-require_relative "rex/book/limit"
-require_relative "rex/book/order"
-require_relative "rex/book/trade"
-require_relative "rex/book/limit_order_book"
-require_relative "rex/book/matcher"
+require_relative "rex/book"
 
 module Rex
   class Error < StandardError; end
diff --git a/lib/rex/book.rb b/lib/rex/book.rb
new file mode 100644
index 0000000..916be26
--- /dev/null
+++ b/lib/rex/book.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative "book/limit"
+require_relative "book/trade"
+require_relative "book/order"
+require_relative "book/limit_order_book"
+require_relative "book/matcher"
+
+module Rex
+  module Book
+  end
+end