diff --git a/Makefile b/Makefile
index f39df76..4045628 100644
--- a/Makefile
+++ b/Makefile
@@ -15,9 +15,23 @@ help: ## Show this help
 	  | awk 'BEGIN{FS=":.*?## "}{printf "  \033[36m%-14s\033[0m %s\n", $$1, $$2}'
 
 .PHONY: setup
-setup: ## Create the venv and install dependencies
+setup: ## Create the venv, install dependencies, and prove the result is usable
 	$(PYTHON) -m venv .venv
 	$(VENV)/bin/pip install -r requirements.txt -r dev-requirements.txt
+	# Exit 0 from pip install is not evidence (D-24) — it is the step's job not
+	# to fail, so a broken result and a working one look identical from here.
+	# On 2026-08-09 the venv existed and pip had exited 0, but sqlalchemy was
+	# declared in requirements.txt and not installed; that surfaced as 11
+	# pytest collection errors that read as broken imports, not as a setup
+	# problem. `--collect-only` exercises every import the suite touches
+	# without running a single test, so it catches exactly that class of
+	# drift and stays cheap. `pip check` was considered too, but it only
+	# verifies the *installed* set's internal consistency against itself —
+	# it would not have caught this case, because sqlalchemy was still
+	# present as another package's transitive dependency even when dropped
+	# from requirements.txt. collect-only checks declared-vs-actually-usable
+	# directly, which is the axis that broke.
+	$(VENV)/bin/python -m pytest --collect-only tests/
 
 .PHONY: test
 test: ## Run the test suite