diff --git a/Makefile b/Makefile
index e1e25a5..ab4b1e7 100644
--- a/Makefile
+++ b/Makefile
@@ -27,11 +27,14 @@ test-headed:
 locust:
 	export DEVPLACE_DATABASE_URL="sqlite:///$(LOCUST_DB)"; \
 	export DEVPLACE_RATE_LIMIT=$(DEVPLACE_RATE_LIMIT); \
+	fuser -k $(LOCUST_PORT)/tcp 2>/dev/null || true; \
+	sleep 1; \
 	mkdir -p $(LOCUST_DB_DIR); \
 	rm -f $(LOCUST_DB); \
 	uvicorn devplacepy.main:app --host 127.0.0.1 --port $(LOCUST_PORT) --backlog 8192 > /tmp/devplace_locust_server.log 2>&1 & \
 	PID=$$!; \
-	while ! curl -s http://127.0.0.1:$(LOCUST_PORT)/ > /dev/null 2>&1; do sleep 0.5; done; \
+	while kill -0 $$PID 2>/dev/null && ! curl -s http://127.0.0.1:$(LOCUST_PORT)/ > /dev/null 2>&1; do sleep 0.5; done; \
+	if ! kill -0 $$PID 2>/dev/null; then echo "Server failed to start (port $(LOCUST_PORT) busy?). See /tmp/devplace_locust_server.log"; exit 1; fi; \
 	locust --host http://127.0.0.1:$(LOCUST_PORT) --web-port $(LOCUST_WEB_PORT); \
 	kill $$PID 2>/dev/null || true; \
 	rm -rf $(LOCUST_DB_DIR)
@@ -39,11 +42,14 @@ locust:
 locust-headless:
 	export DEVPLACE_DATABASE_URL="sqlite:///$(LOCUST_DB)"; \
 	export DEVPLACE_RATE_LIMIT=$(DEVPLACE_RATE_LIMIT); \
+	fuser -k $(LOCUST_PORT)/tcp 2>/dev/null || true; \
+	sleep 1; \
 	mkdir -p $(LOCUST_DB_DIR); \
 	rm -f $(LOCUST_DB); \
 	uvicorn devplacepy.main:app --host 127.0.0.1 --port $(LOCUST_PORT) --backlog 8192 > /tmp/devplace_locust_server.log 2>&1 & \
 	PID=$$!; \
-	while ! curl -s http://127.0.0.1:$(LOCUST_PORT)/ > /dev/null 2>&1; do sleep 0.5; done; \
+	while kill -0 $$PID 2>/dev/null && ! curl -s http://127.0.0.1:$(LOCUST_PORT)/ > /dev/null 2>&1; do sleep 0.5; done; \
+	if ! kill -0 $$PID 2>/dev/null; then echo "Server failed to start (port $(LOCUST_PORT) busy?). See /tmp/devplace_locust_server.log"; exit 1; fi; \
 	locust --host http://127.0.0.1:$(LOCUST_PORT) --headless -u $(LOCUST_USERS) -r $(LOCUST_SPAWN_RATE) --run-time $(LOCUST_RUN_TIME) --html=$(LOCUST_DB_DIR)/report.html; \
 	kill $$PID 2>/dev/null || true; \
 	rm -rf $(LOCUST_DB_DIR)
diff --git a/locustfile.py b/locustfile.py
index 168161d..1e59938 100644
--- a/locustfile.py
+++ b/locustfile.py
@@ -72,7 +72,10 @@ def seed_data(environment, **kwargs):
     import http.cookiejar
 
     created = 0
-    while created < 5:
+    attempts = 0
+    max_attempts = 25
+    while created < 5 and attempts < max_attempts:
+        attempts += 1
         username = random_username()
         email = f"{username}@locust.devplace"
         body = urllib.parse.urlencode({
@@ -88,6 +91,13 @@ def seed_data(environment, **kwargs):
         except Exception as e:
             logger.warning(f"Create seed user failed: {e}")
 
+    if created < 5:
+        logger.error(
+            f"Seeding aborted: only {created}/5 users created after "
+            f"{attempts} attempts. Is the server healthy at {host}?"
+        )
+        return
+
     logger.info(f"Created {len(SEED_USERS)} seed users")
 
     def logged_in_opener(email):