diff --git a/general/genlib/libpcap.xml b/general/genlib/libpcap.xml
index 1e8d8edc99..4419089aab 100644
--- a/general/genlib/libpcap.xml
+++ b/general/genlib/libpcap.xml
@@ -58,6 +58,13 @@ following commands:</para>
 make &amp;&amp;
 make install</command></userinput></screen>
 
+<note><para>Some applications, including <ulink 
+url="http://www.tcpdump.org/">tcpdump</ulink>, require 
+<option>--enable-yydebug</option> passed to <command>configure</command> 
+when building <application>libpcap</application> to enable the parser 
+debugging code. <application>tcpdump</application> will fail to build if 
+you don't pass this parameter.</para></note> 
+
 </sect2>
 
 <sect2>
diff --git a/introduction/welcome/changelog.xml b/introduction/welcome/changelog.xml
index 39b11e8e2c..b34d3e8732 100644
--- a/introduction/welcome/changelog.xml
+++ b/introduction/welcome/changelog.xml
@@ -24,6 +24,7 @@ who wrote what.</para>
 
 <listitem><para>February 11th, 2005 [randy]: Added md5sums to Chapter 18, 
 19 and 20 package instructions; changed FTP download URL in NcFTP and Pine 
+instructions; added a note about using --enable-yydebug to libpcap 
 instructions.</para></listitem>
 
 <listitem><para>February 10th, 2005 [larry]: Updated to emacs-21.4 and