diff --git a/app/serve.py b/app/serve.py
index 0abc47f42..efb4ceea7 100755
--- a/app/serve.py
+++ b/app/serve.py
@@ -100,6 +100,7 @@ def _fixup_deprecated_host_args(arguments):
 show_ulog_file = False
 show_3d_page = False
 show_pid_analysis_page = False
+ulog_file = ''
 if args.file is not None:
     ulog_file = os.path.abspath(args.file)
     show_ulog_file = True
diff --git a/app/tornado_handlers/three_d.py b/app/tornado_handlers/three_d.py
index 5fe414464..b1f6f9fe8 100644
--- a/app/tornado_handlers/three_d.py
+++ b/app/tornado_handlers/three_d.py
@@ -119,6 +119,7 @@ def get(self, *args, **kwargs):
         # - altitude requires an offset (to match the GPS data)
         # - it's worse for some logs where the estimation is bad -> acro flights
         #   (-> add both: user-selectable between GPS & estimated trajectory?)
+        start_timestamp = 0
         for i in range(len(gps_pos.data['timestamp'])):
             t = gps_pos.data['timestamp'][i] + utc_offset
             utctimestamp = datetime.datetime.utcfromtimestamp(t/1.e6).replace(