diff --git a/.gitmodules b/.gitmodules
index 3d07ed7c..bc30442a 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -2,3 +2,9 @@
 	path = extern/pybind11
 	url = https://github.com/sbaldu/pybind11.git
 	branch = master
+[submodule "extern/boost"]
+	path = extern/boost
+	url = https://github.com/boostorg/boost.git
+[submodule "extern/alpaka"]
+	path = extern/alpaka
+	url = https://github.com/cms-patatrack/alpaka.git
diff --git a/extern/alpaka b/extern/alpaka
new file mode 160000
index 00000000..5573fc35
--- /dev/null
+++ b/extern/alpaka
@@ -0,0 +1 @@
+Subproject commit 5573fc351cc1de8d4ffe0db092ad1b3eb9eae177
diff --git a/extern/boost b/extern/boost
new file mode 160000
index 00000000..7e666ef3
--- /dev/null
+++ b/extern/boost
@@ -0,0 +1 @@
+Subproject commit 7e666ef3d6875c6b4bc6838867492b267390d7be