diff --git a/.gitmodules b/.gitmodules
index 0b2349ad42..5fd83ac60d 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -11,3 +11,7 @@
 [submodule "src/Markup/Avalonia.Markup.Xaml/glass"]
 	path = src/Markup/Avalonia.Markup.Xaml/glass
 	url = https://github.com/SuperJMN/glass
+[submodule "src/Markup/Portable.Xaml"]
+	path = src/Markup/Portable.Xaml
+	url = https://github.com/cwensley/Portable.Xaml.git
+	branch = develop
diff --git a/src/Markup/Portable.Xaml b/src/Markup/Portable.Xaml
new file mode 160000
index 0000000000..3c638dd8da
--- /dev/null
+++ b/src/Markup/Portable.Xaml
@@ -0,0 +1 @@
+Subproject commit 3c638dd8dacded6f408f50da60e1ada0f0b223b1