diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ddb03c1f32..29b3f627f8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -4,6 +4,9 @@ variables:
   # Locale settings do not affect the build, but might affect tests.
   LC_ALL: C
 
+  # enable junk filling via jemalloc option
+  MALLOC_CONF: "junk:true"
+
   # automated commits will inherit identification from pipeline trigger
   GIT_AUTHOR_NAME: "$GITLAB_USER_NAME (GitLab job $CI_JOB_ID)"
   GIT_AUTHOR_EMAIL: "$GITLAB_USER_EMAIL"