diff --git a/src/ServiceStack.Authentication.NHibernate/packages.config b/src/ServiceStack.Authentication.NHibernate/packages.config
index 422ff8a..7a7c914 100644
--- a/src/ServiceStack.Authentication.NHibernate/packages.config
+++ b/src/ServiceStack.Authentication.NHibernate/packages.config
@@ -2,5 +2,5 @@
 <packages>
   <package id="FluentNHibernate" version="1.3.0.733" targetFramework="net35" />
   <package id="Iesi.Collections" version="3.3.3.4000" targetFramework="net35" />
-  <package id="NHibernate" version="3.3.3.4001" targetFramework="net35" />
+  <package id="NHibernate" version="3.3.3.4001" targetFramework="net40" />
 </packages>
\ No newline at end of file