diff --git a/src/code-listings/lesson-37/FSharpWeb/packages.config b/src/code-listings/lesson-37/FSharpWeb/packages.config
index 1dabfd8..94e97eb 100644
--- a/src/code-listings/lesson-37/FSharpWeb/packages.config
+++ b/src/code-listings/lesson-37/FSharpWeb/packages.config
@@ -4,7 +4,7 @@
   <package id="Microsoft.AspNet.WebApi.Client" version="5.2.2" targetFramework="net45" />
   <package id="Microsoft.AspNet.WebApi.Core" version="5.2.2" targetFramework="net45" />
   <package id="Microsoft.AspNet.WebApi.Owin" version="5.2.2" targetFramework="net45" />
-  <package id="Microsoft.Owin" version="3.0.0" targetFramework="net45" />
+  <package id="Microsoft.Owin" version="4.1.1" targetFramework="net45" />
   <package id="Microsoft.Owin.Host.SystemWeb" version="3.0.0" targetFramework="net45" />
   <package id="MSBuild.Extension.Pack" version="1.3.0" targetFramework="net45" />
   <package id="Newtonsoft.Json" version="6.0.4" targetFramework="net45" />