diff --git a/.drone.yml b/.drone.yml
index 3cdabce..ffd0685 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -3,7 +3,14 @@ kind: pipeline
 type: docker
 name: default
 
+clone:
+  depth: 1
+
 steps:
+- name: fetch
+  image: alpine/git
+  commands:
+    - git submodule update --init --recursive
 - name: build
   pull: always
   image: gitea.rixxc.de/rixxc/ma-latex:latest
diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..de5d11c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "thesis/cryptobib"]
+	path = thesis/cryptobib
+	url = https://github.com/cryptobib/export
diff --git a/thesis/cryptobib b/thesis/cryptobib
new file mode 160000
index 0000000..c12f97b
--- /dev/null
+++ b/thesis/cryptobib
@@ -0,0 +1 @@
+Subproject commit c12f97b57bba99ca8447ead6617b1b31387ba8ce