diff --git a/pcap_open_offline.3pcap.in b/pcap_open_offline.3pcap.in
index 825b365..3f9f5a2 100644
--- a/pcap_open_offline.3pcap.in
+++ b/pcap_open_offline.3pcap.in
@@ -43,11 +43,15 @@ pcap_t *pcap_fopen_offline(FILE *fp, char *errbuf);
 is called to open a ``savefile'' for reading.
 .PP
 .I fname
-specifies the name of the file to open. The file has
-the same format as those used by
+specifies the name of the file to open. The file can have the pcap file
+format as described in
+.BR pcap-savefile (@MAN_FILE_FORMATS@),
+which is the file format used by, among other programs,
 .BR tcpdump (1)
 and
-.BR tcpslice (1).
+.BR tcpslice (1),
+or can have the pcap-ng file format, although not all pcap-ng files can
+be read.
 The name "-" in a synonym for
 .BR stdin .
 .PP