diff --git a/notebook/tests/launchnotebook.py b/notebook/tests/launchnotebook.py
index 9e84a5964..14132522f 100644
--- a/notebook/tests/launchnotebook.py
+++ b/notebook/tests/launchnotebook.py
@@ -146,31 +146,31 @@ class NotebookTestBase(TestCase):
             if 'asyncio' in sys.modules:
                 import asyncio
                 asyncio.set_event_loop(asyncio.new_event_loop())
-            app = cls.notebook = NotebookApp(
-                port=cls.port,
-                port_retries=0,
-                open_browser=False,
-                config_dir=cls.config_dir,
-                data_dir=cls.data_dir,
-                runtime_dir=cls.runtime_dir,
-                notebook_dir=cls.notebook_dir,
-                base_url=cls.url_prefix,
-                config=config,
-                allow_root=True,
-                token=cls.token,
-            )
-            # don't register signal handler during tests
-            app.init_signal = lambda : None
-            # clear log handlers and propagate to root for nose to capture it
-            # needs to be redone after initialize, which reconfigures logging
-            app.log.propagate = True
-            app.log.handlers = []
-            app.initialize(argv=cls.get_argv())
-            app.log.propagate = True
-            app.log.handlers = []
-            loop = IOLoop.current()
-            loop.add_callback(started.set)
             try:
+                app = cls.notebook = NotebookApp(
+                    port=cls.port,
+                    port_retries=0,
+                    open_browser=False,
+                    config_dir=cls.config_dir,
+                    data_dir=cls.data_dir,
+                    runtime_dir=cls.runtime_dir,
+                    notebook_dir=cls.notebook_dir,
+                    base_url=cls.url_prefix,
+                    config=config,
+                    allow_root=True,
+                    token=cls.token,
+                )
+                # don't register signal handler during tests
+                app.init_signal = lambda : None
+                # clear log handlers and propagate to root for nose to capture it
+                # needs to be redone after initialize, which reconfigures logging
+                app.log.propagate = True
+                app.log.handlers = []
+                app.initialize(argv=cls.get_argv())
+                app.log.propagate = True
+                app.log.handlers = []
+                loop = IOLoop.current()
+                loop.add_callback(started.set)
                 app.start()
             finally:
                 # set the event, so failure to start doesn't cause a hang