diff --git a/wizard-work/beam/CHECK b/wizard-work/beam/CHECK
index 2b8b282..0d138a0 100755
--- a/wizard-work/beam/CHECK
+++ b/wizard-work/beam/CHECK
@@ -1,5 +1,6 @@
 #!/bin/bash
 # CHECK: verify all beam reliability primitives
+set -e
 cd /root/troupe-standup/wizard-work/beam
 python3 -m unittest discover -p 'test_*.py' -v
-exit $?
+python3 toposort/test_toposort.py