diff --git a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs
index bed4fa4aa7a..f4b09ed84e9 100644
--- a/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs
+++ b/src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Input/TextServicesManager.cs
@@ -231,11 +231,16 @@ private bool TextServicesKeystroke(TextServicesContext context, KeyEventArgs key
                     break;
                 default:
                     wParam = KeyInterop.VirtualKeyFromKey(keyArgs.RealKey);
-                    scancode = 0; 
+                    scancode = keyArgs.ScanCode;
                     break;
             }
 
-            lParam = (int)(((uint)scancode << 16) | 1);
+            lParam = (int)((((uint)scancode & 0xFF) << 16) | 1);
+
+            if (keyArgs.IsExtendedKey)
+            {
+                lParam |= 1 << 24;
+            }
 
             if (keyArgs.RoutedEvent == Keyboard.PreviewKeyDownEvent/*keyArgs.IsDown*/)
             {