diff --git a/gui.py b/dev.py
similarity index 51%
rename from gui.py
rename to dev.py
index 5b6b337..49f2983 100644
--- a/gui.py
+++ b/dev.py
@@ -1,6 +1,9 @@
+import sys
 from pathlib import Path
 
+sys.argv.append('--dev')
+
 from flandre.launcher import launch_from_file
 
 if __name__ == '__main__':
-    launch_from_file(Path(__file__).parent / 'gui.toml')
+    launch_from_file(Path(__file__).parent / 'dev.toml')
diff --git a/dev.toml b/dev.toml
new file mode 100644
index 0000000..23b5cd0
--- /dev/null
+++ b/dev.toml
@@ -0,0 +1,2 @@
+[MainUI]
+[ImageCV]
diff --git a/flandre/nodes/Midi.py b/flandre/nodes/Midi.py
index 264cc0f..8b2fd77 100644
--- a/flandre/nodes/Midi.py
+++ b/flandre/nodes/Midi.py
@@ -1,6 +1,5 @@
 import logging
 from threading import Thread
-from unittest import case
 
 import mido
 import zmq