diff --git a/Makefile b/Makefile
index 08cb8e7..07be8de 100644
--- a/Makefile
+++ b/Makefile
@@ -1,2 +1,5 @@
-build-iso:
+build-iso: submodules-update
 	cd nixpkgs/nixos && nix-build -A config.system.build.isoImage -I nixos-config=../../livecd-minimal.nix
+
+submodules-update:
+	git submodule update --remote