diff --git a/manpages/ndndump.rst b/manpages/ndndump.rst
index 95c1904..0872b38 100644
--- a/manpages/ndndump.rst
+++ b/manpages/ndndump.rst
@@ -11,16 +11,16 @@
 Description
 -----------
 
-:program:`ndndump` is a traffic analysis tool that captures Interest and Data packets on the wire,
-and displays brief information about captured packets.
+:program:`ndndump` is a traffic analysis tool that captures Interest, Data, and Nack packets on the
+wire and displays brief information about captured packets.
 
-Currently, :program:`ndndump` is capable of extracting Interest and Data packets from:
+Currently, :program:`ndndump` is capable of extracting Interest, Data, and Nack packets from:
 
-* Ethernet, when bare Interest/Data is transmitted without NDNLP header
+* Ethernet
 * PPP link (e.g., pcap trace from ndnSIM)
 * IPv4 UDP unicast tunnel
 * IPv4 UDP multicast group
-* IPv6 TCP tunnel, when Interest/Data is aligned to the front of a TCP segment
+* IPv4 TCP tunnel, when Interest/Data/Nack is aligned to the front of a TCP segment
 
 Options
 -------
diff --git a/tools/dump/README.md b/tools/dump/README.md
index d99bfe1..cf46ab1 100644
--- a/tools/dump/README.md
+++ b/tools/dump/README.md
@@ -1,6 +1,6 @@
 # ndndump
 
-**ndndump** is a traffic analysis tool that captures Interest and Data packets on the wire,
+**ndndump** is a traffic analysis tool that captures Interest, Data, and Nack packets on the wire
 and displays brief information about captured packets.
 
 Usage example: