diff --git a/src/main/python/keymap_editor.py b/src/main/python/keymap_editor.py
index f075e46..ce2d328 100644
--- a/src/main/python/keymap_editor.py
+++ b/src/main/python/keymap_editor.py
@@ -172,6 +172,9 @@ class KeymapEditor(BasicEditor):
     def set_key(self, keycode):
         """ Change currently selected key to provided keycode """
 
+        if self.container.active_key is None:
+            return
+
         if isinstance(self.container.active_key, EncoderWidget):
             self.set_key_encoder(keycode)
         else: