diff --git a/src/Microsoft.AspNetCore.Hosting/Internal/HostingEnvironmentExtensions.cs b/src/Microsoft.AspNetCore.Hosting/Internal/HostingEnvironmentExtensions.cs
index c4ecca6fa0..b38f997cac 100644
--- a/src/Microsoft.AspNetCore.Hosting/Internal/HostingEnvironmentExtensions.cs
+++ b/src/Microsoft.AspNetCore.Hosting/Internal/HostingEnvironmentExtensions.cs
@@ -63,7 +63,7 @@ namespace Microsoft.AspNetCore.Hosting.Internal
             
             hostingEnvironment.EnvironmentName =
                 options.Environment ??
-                Environment.GetEnvironmentVariable($"ASPNETCORE_{WebHostDefaults.EnvironmentKey}") ??
+                Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT") ??
                 hostingEnvironment.EnvironmentName;
         }
     }