diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 95e7913279fc7fa5410f355c2a1d30f96e4c11b1..1e36c1b81deb41e1c2dcdf9b10251a3783a3dbde 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -68,7 +68,7 @@ build-coq.8.6.1:
   <<: *template
   variables:
     OPAM_PINS: "coq version 8.6.1   coq-mathcomp-ssreflect version 1.6.4"
-    VALIDATE: "1"
+#    VALIDATE: "1" # coqchk fails with a stack overflow
   artifacts:
     paths:
     - build-time.txt