diff --git a/.gitmodules b/.gitmodules
index 0a6bfa1..8679a50 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -13,3 +13,6 @@
 [submodule "lib/DukeNukemZeroHour"]
 	path = lib/DukeNukemZeroHour
 	url = https://github.com/Gillou68310/DukeNukemZeroHour
+[submodule "lib/rt64"]
+	path = lib/rt64
+	url = https://github.com/rt64/rt64
diff --git a/lib/rt64 b/lib/rt64
new file mode 160000
index 0000000..ffb006f
--- /dev/null
+++ b/lib/rt64
@@ -0,0 +1 @@
+Subproject commit ffb006f57043895653668f3812020fa4b0f287b8