diff --git a/pkg/pypi/build.py b/pkg/pypi/build.py
index 3ab8c57..557a648 100644
--- a/pkg/pypi/build.py
+++ b/pkg/pypi/build.py
@@ -26,6 +26,7 @@ INCLUDE_DIRS = [
     os.path.join(ROOT_DIR, "ext/lwip-contrib/ports/unix/port/include"),
     os.path.join(ROOT_DIR, "ext/ZeroTierOne/include"),
     os.path.join(ROOT_DIR, "ext/ZeroTierOne"),
+    os.path.join(ROOT_DIR, "ext/ZeroTierOne/ext"),
     os.path.join(ROOT_DIR, "ext/ZeroTierOne/node"),
     os.path.join(ROOT_DIR, "ext/ZeroTierOne/service"),
     os.path.join(ROOT_DIR, "ext/ZeroTierOne/osdep"),