diff --git a/docs/manpages/nfdc.rst b/docs/manpages/nfdc.rst
index 9de9e0c..67d691c 100644
--- a/docs/manpages/nfdc.rst
+++ b/docs/manpages/nfdc.rst
@@ -39,7 +39,8 @@
         Cost for the RIB entry (default is 0).
 
       ``-e <expiration time>``
-        Expiration time of the RIB entry in milliseconds (default is 3600000).
+        Expiration time of the RIB entry in milliseconds. If not specified, the entry remains in FIB
+        for the lifetime of the associated face.
 
        ``-o <origin>``
         Origin of the registration request (default is 255).