diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ea78e0378f9846bb19640db2bad46f4172650812..e3bfc4509f04d164b1cf5b8c3d586f6a54bd55f7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,6 +5,7 @@ stages:
 
 variables:
   CPU_CORES: "10"
+  OCAML: "ocaml-base-compiler.4.08.1"
 
 .template: &template
   stage: build