diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 16db2a447c1fea91c4eedd6c89fb26b3436abaa2..8d6d4b204408e01b83d602e332147c41bf9bd9c4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -38,6 +38,7 @@ build-coq.8.9.0:
 build-iris.dev:
   <<: *template
   variables:
+    OCAML: "ocaml-base-compiler.4.07.0"
     OPAM_PINS: "coq version 8.10.dev   coq-stdpp.dev git git+https://gitlab.mpi-sws.org/iris/stdpp.git#$STDPP_REV  coq-iris.dev git git+https://gitlab.mpi-sws.org/iris/iris.git#$IRIS_REV"
   except:
   only: