diff --git a/src/Hosting/Abstractions/ref/Microsoft.AspNetCore.Hosting.Abstractions.netcoreapp3.0.cs b/src/Hosting/Abstractions/ref/Microsoft.AspNetCore.Hosting.Abstractions.netcoreapp3.0.cs
index 0f031ee9a7..9d856ad0ed 100644
--- a/src/Hosting/Abstractions/ref/Microsoft.AspNetCore.Hosting.Abstractions.netcoreapp3.0.cs
+++ b/src/Hosting/Abstractions/ref/Microsoft.AspNetCore.Hosting.Abstractions.netcoreapp3.0.cs
@@ -3,6 +3,7 @@
 
 namespace Microsoft.AspNetCore.Hosting
 {
+    [System.ObsoleteAttribute("This type is obsolete and will be removed in a future version. The recommended alternative is Microsoft.Extensions.Hosting.Environments.", false)]
     public static partial class EnvironmentName
     {
         public static readonly string Development;