diff --git a/src/escpos/printer/win32raw.py b/src/escpos/printer/win32raw.py
index ee01c27..e367460 100644
--- a/src/escpos/printer/win32raw.py
+++ b/src/escpos/printer/win32raw.py
@@ -131,7 +131,7 @@ class Win32Raw(Escpos):
         logging.info("Win32Raw printer enabled")
 
     @dependency_win32print
-    def close(self):
+    def close(self) -> None:
         """Close connection to default printer."""
         if not self._device:
             return