diff --git a/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs b/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
index cd9038c99797..e7b3be111228 100644
--- a/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
+++ b/src/Tasks/Microsoft.NET.Build.Tasks/ResolveReadyToRunCompilers.cs
@@ -193,11 +193,11 @@ private bool GetCrossgen2TargetOS(out string targetOS)
             {
                 if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                 {
-                    portablePlatform = "linux";
+                    portablePlatform = "win";
                 }
                 else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
                 {
-                    portablePlatform = "win";
+                    portablePlatform = "linux";
                 }
                 else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
                 {