diff --git a/brozzler/cli.py b/brozzler/cli.py
index 414ab60..87bfa5d 100644
--- a/brozzler/cli.py
+++ b/brozzler/cli.py
@@ -660,6 +660,9 @@ def brozzler_stop_crawl(argv=None):
         except ValueError:
             job_id = args.job_id
         job = brozzler.Job.load(rr, job_id)
+        if not job:
+            logging.fatal('job not found with id=%s', repr(job_id))
+            sys.exit(1)
         job.stop_requested = doublethink.utcnow()
         job.save()
     elif args.site_id:
@@ -668,6 +671,9 @@ def brozzler_stop_crawl(argv=None):
         except ValueError:
             site_id = args.site_id
         site = brozzler.Site.load(rr, site_id)
+        if not site:
+            logging.fatal('site not found with id=%s', repr(site_id))
+            sys.exit(1)
         site.stop_requested = doublethink.utcnow()
         site.save()
 
diff --git a/setup.py b/setup.py
index 227bf00..8fad7fa 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@ def find_package_data(package):
 
 setuptools.setup(
         name='brozzler',
-        version='1.1b11.dev237',
+        version='1.1b11.dev238',
         description='Distributed web crawling with browsers',
         url='https://github.com/internetarchive/brozzler',
         author='Noah Levitt',
diff --git a/tests/test_cli.py b/tests/test_cli.py
index 5eec62a..473d16e 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -21,6 +21,7 @@ import brozzler.cli
 import pkg_resources
 import pytest
 import subprocess
+import doublethink
 
 def cli_commands():
     commands = set(pkg_resources.get_entry_map(
@@ -36,7 +37,6 @@ def cli_commands():
         commands.remove('brozzler-easy')
     return commands
 
-
 @pytest.mark.parametrize('cmd', cli_commands())
 def test_call_entrypoint(capsys, cmd):
     entrypoint = pkg_resources.get_entry_map(
@@ -57,3 +57,22 @@ def test_run_command(capsys, cmd):
         brozzler.__version__, cmd)).encode('ascii')
     assert err == b''
 
+def test_rethinkdb_up():
+    '''Check that rethinkdb is up and running.'''
+    # check that rethinkdb is listening and looks sane
+    rr = doublethink.Rethinker(db='rethinkdb')  # built-in db
+    tbls = rr.table_list().run()
+    assert len(tbls) > 10
+
+def test_stop_nonexistent_crawl(capsys):
+    with pytest.raises(SystemExit):
+        brozzler.cli.brozzler_stop_crawl(['brozzler-stop-crawl', '--site=123'])
+    out, err = capsys.readouterr()
+    assert err.endswith('site not found with id=123\n')
+    assert out == ''
+
+    with pytest.raises(SystemExit):
+        brozzler.cli.brozzler_stop_crawl(['brozzler-stop-crawl', '--job=abc'])
+    out, err = capsys.readouterr()
+    assert err.endswith('''job not found with id='abc'\n''')
+    assert out == ''