diff --git a/README.rst b/README.rst
index f37f6939..825057f0 100644
--- a/README.rst
+++ b/README.rst
@@ -86,6 +86,11 @@ resource) in ``nghttp``, the following package is required:
 
 * libxml2 >= 2.7.7
 
+To enable systemd support in nghttpx, the following package is
+required:
+
+* libsystemd-dev >= 209
+
 The HPACK tools require the following package:
 
 * jansson >= 2.5