diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0737b90cdc10ae97c6cda7842b09d7bd1d5f855c..125546bcf80ae3cb65288b7056b5af0ead0f7287 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