diff --git a/.gitmodules b/.gitmodules
index aa7d19bc..8403d544 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -10,3 +10,11 @@
 	path = external/readerwriterqueue
 	url = https://github.com/cameron314/readerwriterqueue.git
 	shallow = true
+[submodule "external/cnpy"]
+	path = external/cnpy
+	url = https://github.com/paulfd/cnpy.git
+	shallow = true
+[submodule "external/Catch2"]
+	path = external/Catch2
+	url = https://github.com/catchorg/Catch2.git
+	shallow = true
diff --git a/external/Catch2 b/external/Catch2
new file mode 160000
index 00000000..7b865dac
--- /dev/null
+++ b/external/Catch2
@@ -0,0 +1 @@
+Subproject commit 7b865daccc7bba2dcc25a4f0b9ea7348b1b4d61f
diff --git a/external/cnpy b/external/cnpy
new file mode 160000
index 00000000..34693799
--- /dev/null
+++ b/external/cnpy
@@ -0,0 +1 @@
+Subproject commit 34693799ada6cb84be3f588aabbe75f24d010e2f