diff --git a/doc/src/sgml/external-projects.sgml b/doc/src/sgml/external-projects.sgml
index 7d26477123..1d88054c22 100644
--- a/doc/src/sgml/external-projects.sgml
+++ b/doc/src/sgml/external-projects.sgml
@@ -65,42 +65,42 @@
       <entry>DBD::Pg</entry>
       <entry>Perl</entry>
       <entry>Perl DBI driver</entry>
-      <entry><ulink url="http://search.cpan.org/dist/DBD-Pg/">http://search.cpan.org/dist/DBD-Pg/</ulink></entry>
+      <entry><ulink url="http://search.cpan.org/dist/DBD-Pg/"></ulink></entry>
      </row>
 
      <row>
       <entry>JDBC</entry>
       <entry>JDBC</entry>
       <entry>Type 4 JDBC driver</entry>
-      <entry><ulink url="http://jdbc.postgresql.org/">http://jdbc.postgresql.org/</ulink></entry>
+      <entry><ulink url="http://jdbc.postgresql.org/"></ulink></entry>
      </row>
 
      <row>
       <entry>libpqxx</entry>
       <entry>C++</entry>
       <entry>New-style C++ interface</entry>
-      <entry><ulink url="http://pqxx.org/">http://pqxx.org/</ulink></entry>
+      <entry><ulink url="http://pqxx.org/"></ulink></entry>
      </row>
 
      <row>
       <entry>Npgsql</entry>
       <entry>.NET</entry>
       <entry>.NET data provider</entry>
-      <entry><ulink url="http://www.npgsql.org/">http://www.npgsql.org/</ulink></entry>
+      <entry><ulink url="http://www.npgsql.org/"></ulink></entry>
      </row>
 
      <row>
       <entry>pgtclng</entry>
       <entry>Tcl</entry>
       <entry></entry>
-      <entry><ulink url="http://sourceforge.net/projects/pgtclng/">http://sourceforge.net/projects/pgtclng/</ulink></entry>
+      <entry><ulink url="http://sourceforge.net/projects/pgtclng/"></ulink></entry>
      </row>
 
      <row>
       <entry>psqlODBC</entry>
       <entry>ODBC</entry>
       <entry>ODBC driver</entry>
-      <entry><ulink url="https://odbc.postgresql.org/">https://odbc.postgresql.org/</ulink></entry>
+      <entry><ulink url="https://odbc.postgresql.org/"></ulink></entry>
      </row>
 
      <row>
@@ -172,43 +172,43 @@
      <row>
       <entry>PL/Java</entry>
       <entry>Java</entry>
-      <entry><ulink url="https://github.com/tada/pljava">https://github.com/tada/pljava</ulink></entry>
+      <entry><ulink url="https://github.com/tada/pljava"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/PHP</entry>
       <entry>PHP</entry>
-      <entry><ulink url="http://www.commandprompt.com/community/plphp/">http://www.commandprompt.com/community/plphp/</ulink></entry>
+      <entry><ulink url="http://www.commandprompt.com/community/plphp/"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/Py</entry>
       <entry>Python</entry>
-      <entry><ulink url="http://python.projects.postgresql.org/backend/">http://python.projects.postgresql.org/backend/</ulink></entry>
+      <entry><ulink url="http://python.projects.postgresql.org/backend/"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/R</entry>
       <entry>R</entry>
-      <entry><ulink url="http://www.joeconway.com/plr/">http://www.joeconway.com/plr/</ulink></entry>
+      <entry><ulink url="http://www.joeconway.com/plr/"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/Ruby</entry>
       <entry>Ruby</entry>
-      <entry><ulink url="http://raa.ruby-lang.org/project/pl-ruby/">http://raa.ruby-lang.org/project/pl-ruby/</ulink></entry>
+      <entry><ulink url="http://raa.ruby-lang.org/project/pl-ruby/"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/Scheme</entry>
       <entry>Scheme</entry>
-      <entry><ulink url="http://plscheme.projects.postgresql.org/">http://plscheme.projects.postgresql.org/</ulink></entry>
+      <entry><ulink url="http://plscheme.projects.postgresql.org/"></ulink></entry>
      </row>
 
      <row>
       <entry>PL/sh</entry>
       <entry>Unix shell</entry>
-      <entry><ulink url="https://github.com/petere/plsh">https://github.com/petere/plsh</ulink></entry>
+      <entry><ulink url="https://github.com/petere/plsh"></ulink></entry>
      </row>
     </tbody>
    </tgroup>
diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml
index 087cd0a90c..cda05f578a 100644
--- a/doc/src/sgml/runtime.sgml
+++ b/doc/src/sgml/runtime.sgml
@@ -1428,7 +1428,7 @@ $ <userinput>sysctl -w vm.nr_hugepages=3170</userinput>
    <para>
     For a detailed description of the <productname>Linux</productname> huge
     pages feature have a look
-    at <ulink url="https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt">https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt</ulink>.
+    at <ulink url="https://www.kernel.org/doc/Documentation/vm/hugetlbpage.txt"></ulink>.
    </para>
 
   </sect2>