diff --git a/dotnet-desktop-guide/framework/wpf/advanced/attached-properties-overview b/dotnet-desktop-guide/framework/wpf/advanced/attached-properties-overview.md
similarity index 100%
rename from dotnet-desktop-guide/framework/wpf/advanced/attached-properties-overview
rename to dotnet-desktop-guide/framework/wpf/advanced/attached-properties-overview.md