diff --git a/C#/Sample-dotnet-4.5/PayPing.Ipg/packages.config b/C#/Sample-dotnet-4.5/PayPing.Ipg/packages.config
index 5aae836..41148bf 100644
--- a/C#/Sample-dotnet-4.5/PayPing.Ipg/packages.config
+++ b/C#/Sample-dotnet-4.5/PayPing.Ipg/packages.config
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Antlr" version="3.5.0.2" targetFramework="net462" />
-  <package id="bootstrap" version="3.3.7" targetFramework="net462" />
+  <package id="bootstrap" version="5.0.0" targetFramework="net462" />
   <package id="jQuery" version="3.3.1" targetFramework="net462" />
   <package id="jQuery.Validation" version="1.17.0" targetFramework="net462" />
   <package id="Microsoft.AspNet.Mvc" version="5.2.4" targetFramework="net462" />