diff --git a/.gitmodules b/.gitmodules
index e3b6883..d09e5fe 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -5,3 +5,7 @@
 [submodule "seed/stage0-posix"]
 	path = seed/stage0-posix
 	url = https://github.com/oriansj/stage0-posix
+
+[submodule "builder-hex0"]
+	path = builder-hex0
+	url = https://github.com/ironmeld/builder-hex0
diff --git a/builder-hex0 b/builder-hex0
new file mode 160000
index 0000000..8a6be6d
--- /dev/null
+++ b/builder-hex0
@@ -0,0 +1 @@
+Subproject commit 8a6be6d30fda0357fdeb4aa4bbbc6d475f9869b2