diff --git a/manpages/ndnpoke.rst b/manpages/ndnpoke.rst
index caa7753..d92ba43 100644
--- a/manpages/ndnpoke.rst
+++ b/manpages/ndnpoke.rst
@@ -50,6 +50,8 @@
 
 2: Malformed command line
 
+5: Prefix registration failed
+
 Example
 -------