diff --git a/Makefile b/Makefile
index e7e4348..5a8365e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,9 @@
 all:
+	@if [ ! -f libopencm3/Makefile ]; then \
+		echo "Initialising git submodules..." ;\
+		git submodule init ;\
+		git submodule update ;\
+	fi
 	$(MAKE) -C libopencm3 lib
 	$(MAKE) -C src