diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000000000000000000000000000000000..3312d0c07ab0da3d000ff8773e2a15e8d1c2e46c
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,4 @@
+[submodule "dependencies/urv-core"]
+	path = dependencies/urv-core
+	url = ssh://git@ohwr.org:7999/project/urv-core.git
+	branch = hydra
diff --git a/dependencies/urv-core b/dependencies/urv-core
new file mode 160000
index 0000000000000000000000000000000000000000..48681306a68561bfe1b6b627a4b2a05ccea899a3
--- /dev/null
+++ b/dependencies/urv-core
@@ -0,0 +1 @@
+Subproject commit 48681306a68561bfe1b6b627a4b2a05ccea899a3