diff --git a/samples/Books Web API/Books.Api/packages.config b/samples/Books Web API/Books.Api/packages.config
index 1e3e2057..038e1bac 100644
--- a/samples/Books Web API/Books.Api/packages.config	
+++ b/samples/Books Web API/Books.Api/packages.config	
@@ -19,7 +19,7 @@
   <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.3" targetFramework="net45" />
   <package id="Microsoft.AspNet.WebPages" version="3.2.3" targetFramework="net45" />
   <package id="Microsoft.jQuery.Unobtrusive.Validation" version="3.2.3" targetFramework="net45" />
-  <package id="Microsoft.Owin" version="3.0.1" targetFramework="net45" />
+  <package id="Microsoft.Owin" version="4.0.0" targetFramework="net45" />
   <package id="Microsoft.Owin.Host.SystemWeb" version="3.0.1" targetFramework="net45" />
   <package id="Microsoft.Owin.Security" version="3.0.1" targetFramework="net45" />
   <package id="Microsoft.Owin.Security.Cookies" version="3.0.1" targetFramework="net45" />