diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 92495493ca9ff72f6d8f87e398d7132af80be153..548002218ab26d040bd916d74e27ce70c2efe6a6 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