diff --git a/compat/mingw.c b/compat/mingw.c
index 0e851ecae2..695eca95b2 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2672,6 +2672,9 @@ static void setup_windows_environment(void)
 		if (!tmp && (tmp = getenv("USERPROFILE")))
 			setenv("HOME", tmp, 1);
 	}
+
+	if (!getenv("LC_ALL") && !getenv("LC_CTYPE") && !getenv("LANG"))
+		setenv("LC_CTYPE", "C.UTF-8", 1);
 }
 
 static PSID get_current_user_sid(void)