diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index bd2d52cc1186c2125c41c237e41279a2d8841375..2fb8ce44aa9ff0a6ad0fa00068a830f39b4cd6c1 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