diff --git a/usb_acpi.py b/usb_acpi.py
index 12aa441..44e92d6 100644
--- a/usb_acpi.py
+++ b/usb_acpi.py
@@ -1,3 +1,4 @@
+import sys
 import time
 
 with open('/dev/hidg0', 'wb') as f: