diff --git a/gitlab/ci_template.yml b/gitlab/ci_template.yml
index 5b66b6bb5c..ebbea4ac52 100644
--- a/gitlab/ci_template.yml
+++ b/gitlab/ci_template.yml
@@ -10,6 +10,7 @@ stages:
 variables:
   GIT_STRATEGY: none
   DEFAULT_MESON_ARGS: >
+    --werror
     -Dpython=enabled
     -Dlibav=enabled
     -Dugly=enabled