diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 408c6b0cf..8c1a0698c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -18,6 +18,7 @@ build:debian-8-mini:
   image: $REGISTRY_HUB:debian-8-mini
   variables:
     CONFIGURE_OPTS: "$CONFIGURE_MINI"
+    MAKE_FLAGS: "CFLAGS=-Werror"
   <<: *build_definition
 
 build:debian-8-full: