diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000..e5dd2cf084
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "extensions/lib/bullet3"]
+	path = extensions/lib/bullet3
+	url = https://github.com/bulletphysics/bullet3.git
diff --git a/extensions/lib/bullet3 b/extensions/lib/bullet3
new file mode 160000
index 0000000000..30ebb32228
--- /dev/null
+++ b/extensions/lib/bullet3
@@ -0,0 +1 @@
+Subproject commit 30ebb322285809bde98959e10e73e5acb9981efc