diff --git a/.gitmodules b/.gitmodules
index 194174e..b5a0ed6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -4,3 +4,6 @@
 [submodule "external/fmtlib"]
 	path = external/fmtlib
 	url = https://github.com/fmtlib/fmt
+[submodule "external/gtest"]
+	path = external/gtest
+	url = https://github.com/google/googletest.git
diff --git a/external/gtest b/external/gtest
new file mode 160000
index 0000000..0953a17
--- /dev/null
+++ b/external/gtest
@@ -0,0 +1 @@
+Subproject commit 0953a17a4281fc26831da647ad3fcd5e21e6473b