diff --git a/docs/nmap-install.xml b/docs/nmap-install.xml
index adefa1429..b65047200 100644
--- a/docs/nmap-install.xml
+++ b/docs/nmap-install.xml
@@ -411,7 +411,14 @@ I would run <command>./configure --prefix=<replaceable>/home/fyodor</replaceable
 <listitem><indexterm><primary>Zenmap</primary><secondary>disabling</secondary></indexterm><para>This option prevents the Zenmap graphical frontend from being installed.  Normally the build system checks your system for requirements such as the Python scripting language and then installs Zenmap if they are all available.</para></listitem></varlistentry>
 
 <varlistentry><term><option>--with-openssl=<replaceable>directoryname</replaceable></option></term>
-<listitem><indexterm><primary>OpenSSL</primary><secondary>disabling</secondary></indexterm><para>The version detection system and Nmap Scripting Engine are able to probe SSL-encrypted services using the free OpenSSL libraries.  Normally the Nmap build system looks for these libraries on your system and include this capability if they are found.  If they are in a location your compiler does not search for by default, but you still want them to be used, specify <option>--with-openssl=<replaceable>directoryname</replaceable></option>.  Nmap then looks in <replaceable>directoryname</replaceable>/libs for the OpenSSL libraries themselves and <replaceable>directoryname</replaceable>/include for the necessary header files.  Specify <option>--without-openssl</option> to disable SSL entirely.</para></listitem></varlistentry>
+<listitem>
+<indexterm><primary>OpenSSL</primary><secondary>disabling</secondary></indexterm>
+<para>The version detection system and Nmap Scripting Engine are able to probe SSL-encrypted services using the free OpenSSL libraries.  Normally the Nmap build system looks for these libraries on your system and include this capability if they are found.  If they are in a location your compiler does not search for by default, but you still want them to be used, specify <option>--with-openssl=<replaceable>directoryname</replaceable></option>.  Nmap then looks in <replaceable>directoryname</replaceable>/libs for the OpenSSL libraries themselves and <replaceable>directoryname</replaceable>/include for the necessary header files.  Specify <option>--without-openssl</option> to disable SSL entirely.</para>
+
+<indexterm><primary>OpenSSL</primary><secondary>packages required for</secondary></indexterm>
+<para>Some distributions ship with user OpenSSL libraries that allow running programs, but not the developer files needed to compile them. Without these developer packages, Nmap will not have OpenSSL support. On Debian-based systems<indexterm><primary>Debian</primary></indexterm>, install the <literal>libssl-dev</literal> package.<indexterm><primary><literal>libssl-dev</literal> package</primary></indexterm> On Red Hat&ndash;based systems,<indexterm><primary>Red Hat</primary></indexterm> install <literal>libopenssl-devel</literal>.<indexterm><primary><literal>libopenssl-devel</literal></primary></indexterm>
+</para>
+</listitem></varlistentry>
 
 <varlistentry><term><option>--with-libpcap=<replaceable>directoryname</replaceable></option></term>
 <listitem><para>Nmap uses the <ulink url="http://www.tcpdump.org">Libpcap library</ulink> for capturing raw IP packets.  Nmap normally looks for an existing copy of Libpcap on your system and uses that if the version number and platform is appropriate.  Otherwise Nmap includes its own recent copy of Libpcap, which has been modified for improved Linux functionality.  The specific changes are described in <filename>libpcap/NMAP_MODIFICATIONS</filename> in the Nmap source directory.  Because of these Linux-related changes, Nmap always uses its own Libpcap by default on that platform.  If you wish to force Nmap to link with your own Libpcap, pass the option <option>--with-libpcap=<replaceable>directoryname</replaceable></option> to <application>configure</application>.  Nmap then expects the Libpcap library to be in <filename><replaceable>directoryname</replaceable>/lib/libpcap.a</filename> and the include files to be in <filename><replaceable>directoryname</replaceable>/include</filename>.  Nmap will always use the version of Libpcap included in its tarball if you specify <option>--with-libpcap=included</option>.