diff --git a/.gitmodules b/.gitmodules
index 731adc3..3e17d8b 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,3 +1,6 @@
 [submodule "lib/N64ModernRuntime"]
 	path = lib/N64ModernRuntime
 	url = https://github.com/sonicdcer/N64ModernRuntime
+[submodule "lib/RmlUi"]
+	path = lib/RmlUi
+	url = https://github.com/mikke89/RmlUi
diff --git a/lib/RmlUi b/lib/RmlUi
new file mode 160000
index 0000000..4462a47
--- /dev/null
+++ b/lib/RmlUi
@@ -0,0 +1 @@
+Subproject commit 4462a47276e5a52394d6b5848b6e86f346c6a8d3