diff --git a/src/main/docbook/xsl/xslthl-config.xml b/src/main/docbook/xsl/xslthl-config.xml
index e4d677f..e354da1 100644
--- a/src/main/docbook/xsl/xslthl-config.xml
+++ b/src/main/docbook/xsl/xslthl-config.xml
@@ -19,5 +19,5 @@
 	<highlighter id="properties" file="./xslthl/properties-hl.xml" />
 	<highlighter id="json" file="./xslthl/json-hl.xml" />
 	<highlighter id="yaml" file="./xslthl/yaml-hl.xml" />
-	<namespace prefix="xslthl" uri="http://xslthl.sf.net" />
+	<namespace prefix="xslthl" uri="http://xslthl.sourceforge.net/" />
 </xslthl-config>
diff --git a/src/main/docbook/xsl/xslthl/bourne-hl.xml b/src/main/docbook/xsl/xslthl/bourne-hl.xml
index e2cd98d..90408ac 100644
--- a/src/main/docbook/xsl/xslthl/bourne-hl.xml
+++ b/src/main/docbook/xsl/xslthl/bourne-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for SH
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2010 Mathieu Malaterre
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/c-hl.xml b/src/main/docbook/xsl/xslthl/c-hl.xml
index 176cc37..7363dba 100644
--- a/src/main/docbook/xsl/xslthl/c-hl.xml
+++ b/src/main/docbook/xsl/xslthl/c-hl.xml
@@ -3,7 +3,7 @@
 Syntax highlighting definition for C
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/cpp-hl.xml b/src/main/docbook/xsl/xslthl/cpp-hl.xml
index ef83c4f..b31f736 100644
--- a/src/main/docbook/xsl/xslthl/cpp-hl.xml
+++ b/src/main/docbook/xsl/xslthl/cpp-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for C++
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/csharp-hl.xml b/src/main/docbook/xsl/xslthl/csharp-hl.xml
index d57e631..0937334 100644
--- a/src/main/docbook/xsl/xslthl/csharp-hl.xml
+++ b/src/main/docbook/xsl/xslthl/csharp-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for C#
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/css-hl.xml b/src/main/docbook/xsl/xslthl/css-hl.xml
index 164c48c..21439ae 100644
--- a/src/main/docbook/xsl/xslthl/css-hl.xml
+++ b/src/main/docbook/xsl/xslthl/css-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for CSS files
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2011-2012 Martin Hujer, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
@@ -26,7 +26,7 @@ freely, subject to the following restrictions:
 Martin Hujer <mhujer at users.sourceforge.net>
 Michiel Hendriks <elmuerte at users.sourceforge.net>
 
-Reference: http://www.w3.org/TR/CSS21/propidx.html
+Reference: https://www.w3.org/TR/CSS21/propidx.html
 
 -->
 <highlighters>
diff --git a/src/main/docbook/xsl/xslthl/html-hl.xml b/src/main/docbook/xsl/xslthl/html-hl.xml
index 5b6761b..366cd46 100644
--- a/src/main/docbook/xsl/xslthl/html-hl.xml
+++ b/src/main/docbook/xsl/xslthl/html-hl.xml
@@ -7,7 +7,7 @@
   myxml-hl.xml - konfigurace zvyraznovace XML, ktera zvlast zvyrazni
                  HTML elementy a XSL elementy
 
-  This file has been customized for the Asciidoctor project (http://asciidoctor.org).
+  This file has been customized for the Asciidoctor project (https://asciidoctor.org).
 -->
 <highlighters>
   <highlighter type="xml">
diff --git a/src/main/docbook/xsl/xslthl/ini-hl.xml b/src/main/docbook/xsl/xslthl/ini-hl.xml
index 34c1036..6bd60b3 100644
--- a/src/main/docbook/xsl/xslthl/ini-hl.xml
+++ b/src/main/docbook/xsl/xslthl/ini-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for ini files
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/java-hl.xml b/src/main/docbook/xsl/xslthl/java-hl.xml
index f7bb164..4fe3c1f 100644
--- a/src/main/docbook/xsl/xslthl/java-hl.xml
+++ b/src/main/docbook/xsl/xslthl/java-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Java
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/javascript-hl.xml b/src/main/docbook/xsl/xslthl/javascript-hl.xml
index 99b8a71..9162040 100644
--- a/src/main/docbook/xsl/xslthl/javascript-hl.xml
+++ b/src/main/docbook/xsl/xslthl/javascript-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for JavaScript
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/perl-hl.xml b/src/main/docbook/xsl/xslthl/perl-hl.xml
index 73d71cc..c8a4d59 100644
--- a/src/main/docbook/xsl/xslthl/perl-hl.xml
+++ b/src/main/docbook/xsl/xslthl/perl-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Perl
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/php-hl.xml b/src/main/docbook/xsl/xslthl/php-hl.xml
index 1da25b8..3ea1578 100644
--- a/src/main/docbook/xsl/xslthl/php-hl.xml
+++ b/src/main/docbook/xsl/xslthl/php-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for PHP
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/properties-hl.xml b/src/main/docbook/xsl/xslthl/properties-hl.xml
index 775f2f1..8205aac 100644
--- a/src/main/docbook/xsl/xslthl/properties-hl.xml
+++ b/src/main/docbook/xsl/xslthl/properties-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Java
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/python-hl.xml b/src/main/docbook/xsl/xslthl/python-hl.xml
index a467443..72bf0db 100644
--- a/src/main/docbook/xsl/xslthl/python-hl.xml
+++ b/src/main/docbook/xsl/xslthl/python-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Python
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/ruby-hl.xml b/src/main/docbook/xsl/xslthl/ruby-hl.xml
index d105640..a2cee72 100644
--- a/src/main/docbook/xsl/xslthl/ruby-hl.xml
+++ b/src/main/docbook/xsl/xslthl/ruby-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for Ruby
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2005-2008 Michal Molhanec, Jirka Kosek, Michiel Hendriks
 
 This software is provided 'as-is', without any express or implied
diff --git a/src/main/docbook/xsl/xslthl/sql2003-hl.xml b/src/main/docbook/xsl/xslthl/sql2003-hl.xml
index ac1d5d0..65c08a3 100644
--- a/src/main/docbook/xsl/xslthl/sql2003-hl.xml
+++ b/src/main/docbook/xsl/xslthl/sql2003-hl.xml
@@ -4,7 +4,7 @@
 Syntax highlighting definition for SQL:1999
 
 xslthl - XSLT Syntax Highlighting
-http://sourceforge.net/projects/xslthl/
+https://sourceforge.net/projects/xslthl/
 Copyright (C) 2012 Michiel Hendriks, Martin Hujer, k42b3
 
 This software is provided 'as-is', without any express or implied