diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..c0c0ffa3
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "references/FluentAssertions"]
+	path = references/FluentAssertions
+	url = https://github.com/dennisdoomen/fluentassertions
diff --git a/references/FluentAssertions b/references/FluentAssertions
new file mode 160000
index 00000000..5c9513b5
--- /dev/null
+++ b/references/FluentAssertions
@@ -0,0 +1 @@
+Subproject commit 5c9513b5c8a267af70a35ddeaf39ce7c76228699