diff --git a/README.txt b/README.txt
index 57d1b25d5b..055ae9f6b8 100644
--- a/README.txt
+++ b/README.txt
@@ -20,7 +20,7 @@ system. Textpattern is both free and open source.
 
 * The Textpattern FAQ is available at http://textpattern.com/faq/
 * In-depth documentation and a comprehensive tag index is available in the
-  Textpattern user documentation at http://docs.textpattern.io
+  Textpattern user documentation at https://docs.textpattern.io
 * You can get support and information via:
    Forum:    https://forum.textpattern.io/
    Twitter:  http://textpattern.com/@textpattern
@@ -111,5 +111,5 @@ system. Textpattern is both free and open source.
 == Contributing ==
 
 Want to help out with the development of Textpattern CMS? Please refer to the
-Contributing documentation http://docs.textpattern.io/development/contributing
+Contributing documentation https://docs.textpattern.io/development/contributing
 for full details.
diff --git a/textpattern/include/txp_tag.php b/textpattern/include/txp_tag.php
index 8397ebe6c4..79cd5b6372 100644
--- a/textpattern/include/txp_tag.php
+++ b/textpattern/include/txp_tag.php
@@ -102,7 +102,7 @@ public function renderTagHelp($name, $panel)
                 hed(gTxt('tag_'.$this->tagname), 2).
                 href(
                     gTxt('documentation').sp.span(gTxt('opens_external_link'), array('class' => 'ui-icon ui-icon-extlink')),
-                    'http://docs.textpattern.io/tags/'.$this->tagname,
+                    'https://docs.textpattern.io/tags/'.$this->tagname,
                     array(
                         'class'  => 'txp-tagbuilder-docs-link',
                         'rel'    => 'external',
diff --git a/textpattern/setup/article.body.textile b/textpattern/setup/article.body.textile
index 968b21fe66..f6a1d5b15b 100644
--- a/textpattern/setup/article.body.textile
+++ b/textpattern/setup/article.body.textile
@@ -14,6 +14,6 @@ h3. What do you want to do next?
 
 There is a host of "Frequently Asked Questions":http://textpattern.com/faq/ to help you get started.
 
-"Textpattern tags":http://docs.textpattern.io/tags/, their attributes and values are explained and sampled within the "Textpattern User Documentation":http://docs.textpattern.io/, where you will also find valuable tips and tutorials.
+"Textpattern tags":https://docs.textpattern.io/tags/, their attributes and values are explained and sampled within the "Textpattern User Documentation":https://docs.textpattern.io/, where you will also find valuable tips and tutorials.
 
 There's also a crowd of friendly, helpful people over at the "Textpattern support forum":https://forum.textpattern.io/. Come and pay a visit!
diff --git a/textpattern/setup/txpsql.php b/textpattern/setup/txpsql.php
index 157c078503..4bd4605d5d 100644
--- a/textpattern/setup/txpsql.php
+++ b/textpattern/setup/txpsql.php
@@ -315,7 +315,7 @@
 ) $tabletype ";
 
 $create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (1, NOW(), 'textpattern', 'http://textpattern.com/',             'Textpattern Website',            '10', '', '')";
-$create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (2, NOW(), 'textpattern', 'http://docs.textpattern.io/',         'Textpattern User Documentation', '20', '', '')";
+$create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (2, NOW(), 'textpattern', 'https://docs.textpattern.io/',         'Textpattern User Documentation', '20', '', '')";
 $create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (3, NOW(), 'textpattern', 'http://textpattern.org/',             'Textpattern Resources',          '30', '', '')";
 $create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (4, NOW(), 'textpattern', 'http://textpattern.com/@textpattern', '@textpattern',                   '40', '', '')";
 $create_sql[] = "INSERT INTO `".PFX."txp_link` VALUES (5, NOW(), 'textpattern', 'http://textpattern.com/+',            '+Textpattern CMS',               '50', '', '')";
diff --git a/textpattern/update/_update.php b/textpattern/update/_update.php
index 7530cb74cf..a6d8f4e484 100644
--- a/textpattern/update/_update.php
+++ b/textpattern/update/_update.php
@@ -116,7 +116,7 @@ function newest_file()
 
 // Invite optional third parties to the update experience
 // Convention: Put custom code into file(s) at textpattern/update/custom/post-update-abc-foo.php
-// where 'abc' is the third party's reserved prefix (@see http://docs.textpattern.io/development/plugin-developer-prefixes)
+// where 'abc' is the third party's reserved prefix (@see https://docs.textpattern.io/development/plugin-developer-prefixes)
 // and 'foo' is whatever. The execution order among all files is undefined.
 $files = glob(txpath.'/update/custom/post-update*.php');