diff --git a/checker/checker.sh b/checker/checker.sh
index 95d644b3d826086452ab43e399b36598a990f80a..0dc92c50d04f8964eff532d5f623addb8275f4c9 100755
--- a/checker/checker.sh
+++ b/checker/checker.sh
@@ -2,6 +2,9 @@
 
 cd "$(dirname "$0")" || exit 1
 
+# Mark for Moodle trace cleanup
+[ -n "$CI" ] && echo "VMCHECKER_TRACE_CLEANUP\n"
+
 EXECUTABLE="../src/perfect"
 TIMEOUT_DURATION=10