diff --git a/Package.swift b/Package.swift
index 81e500f..e1b55cf 100644
--- a/Package.swift
+++ b/Package.swift
@@ -20,7 +20,13 @@ let package = Package(
             ],
             sources: ["library"],
             cxxSettings: [
+                .headerSearchPath("../ASIO/asio/include"),
                 .headerSearchPath("../OpenVPN3"),
+                .define("ASIO_STANDALONE"),
+                .define("ASIO_NO_DEPRECATED"),
+                .define("ASIO_HAS_STD_STRING_VIEW"),
+                .define("USE_ASIO"),
+                .define("USE_ASIO_THREADLOCAL")
             ]
         ),
         .target(