diff --git a/Makefile.builder b/Makefile.builder
index 098463d..146392e 100644
--- a/Makefile.builder
+++ b/Makefile.builder
@@ -1,2 +1,2 @@
 MIRAGE_KERNEL_NAME = qubes_firewall.xen
-OCAML_VERSION ?= 4.07.1
+OCAML_VERSION ?= 4.08.0