diff --git a/combobox.py b/combobox.py
index e62abf00..e4be2c6a 100644
--- a/combobox.py
+++ b/combobox.py
@@ -1,3 +1,4 @@
+import sys
 try:
     from PyQt5.QtWidgets import QWidget, QHBoxLayout, QComboBox
 except ImportError: