diff --git a/setup.py b/setup.py
index 1ec0bb0da..db9cf8be8 100644
--- a/setup.py
+++ b/setup.py
@@ -106,6 +106,7 @@ if windows_check():
         "-DTORRENT_LINKING_SHARED",
         "-DWIN32",
         "-DUNICODE",
+        "-D_UNICODE",
         "/GR",
         "/Zc:wchar_t",
         ]