diff --git a/doc/Makefile b/doc/Makefile
index b3d458c8..1aed3a71 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -9,7 +9,7 @@ BUILDDIR      = _build
 
 # User-friendly check for sphinx-build
 ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
+$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from https://www.sphinx-doc.org/)
 endif
 
 # Internal variables.
diff --git a/doc/make.bat b/doc/make.bat
index 965332d1..c93bab72 100644
--- a/doc/make.bat
+++ b/doc/make.bat
@@ -56,7 +56,7 @@ if errorlevel 9009 (
 	echo.may add the Sphinx directory to PATH.
 	echo.
 	echo.If you don't have Sphinx installed, grab it from
-	echo.http://sphinx-doc.org/
+	echo.https://www.sphinx-doc.org/
 	exit /b 1
 )
 
diff --git a/doc/pyproject_toml.rst b/doc/pyproject_toml.rst
index 644d2448..fbd21476 100644
--- a/doc/pyproject_toml.rst
+++ b/doc/pyproject_toml.rst
@@ -88,7 +88,7 @@ description
 readme
   A path (relative to the .toml file) to a file containing a longer description
   of your package to show on PyPI. This should be written in `reStructuredText
-  <http://docutils.sourceforge.net/docs/user/rst/quickref.html>`_, Markdown or
+  <https://docutils.sourceforge.io/docs/user/rst/quickref.html>`_, Markdown or
   plain text, and the filename should have the appropriate extension
   (``.rst``, ``.md`` or ``.txt``). Alternatively, ``readme`` can be a table with
   either a ``file`` key (a relative path) or a ``text`` key (literal text), and
diff --git a/flit/init.py b/flit/init.py
index e402a3e1..0ce48004 100644
--- a/flit/init.py
+++ b/flit/init.py
@@ -190,7 +190,7 @@ def initialise(self):
             home_page_default = None
         home_page = self.prompt_text('Home page', home_page_default, self.validate_homepage,
                                      retry_msg="Should start with http:// or https:// - try again.")
-        license = self.prompt_options('Choose a license (see http://choosealicense.com/ for more info)',
+        license = self.prompt_options('Choose a license (see https://choosealicense.com/ for more info)',
                     license_choices, self.defaults.get('license'))
 
         readme = self.find_readme()
diff --git a/flit/install.py b/flit/install.py
index a7035eb1..aad3a2c3 100644
--- a/flit/install.py
+++ b/flit/install.py
@@ -53,8 +53,8 @@ def test_writable_dir(path):
     return _test_writable_dir_win(path)
 
 def _test_writable_dir_win(path):
-    # os.access doesn't work on Windows: http://bugs.python.org/issue2528
-    # and we can't use tempfile: http://bugs.python.org/issue22107
+    # os.access doesn't work on Windows: https://github.com/python/cpython/issues/46780
+    # and we can't use tempfile: https://github.com/python/cpython/issues/66305
     basename = 'accesstest_deleteme_fishfingers_custard_'
     alphabet = 'abcdefghijklmnopqrstuvwxyz0123456789'
     for i in range(10):
diff --git a/flit_core/tests_core/samples/EG_README.rst b/flit_core/tests_core/samples/EG_README.rst
index a742974e..0d5e81c1 100644
--- a/flit_core/tests_core/samples/EG_README.rst
+++ b/flit_core/tests_core/samples/EG_README.rst
@@ -1,4 +1,4 @@
 This is an example long description for tests to load.
 
 This file is `valid reStructuredText
-<http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html>`_.
+<https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`_.
diff --git a/flit_core/tests_core/samples/ns1-pkg/EG_README.rst b/flit_core/tests_core/samples/ns1-pkg/EG_README.rst
index a742974e..0d5e81c1 100644
--- a/flit_core/tests_core/samples/ns1-pkg/EG_README.rst
+++ b/flit_core/tests_core/samples/ns1-pkg/EG_README.rst
@@ -1,4 +1,4 @@
 This is an example long description for tests to load.
 
 This file is `valid reStructuredText
-<http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html>`_.
+<https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`_.
diff --git a/tests/samples/EG_README.rst b/tests/samples/EG_README.rst
index a742974e..0d5e81c1 100644
--- a/tests/samples/EG_README.rst
+++ b/tests/samples/EG_README.rst
@@ -1,4 +1,4 @@
 This is an example long description for tests to load.
 
 This file is `valid reStructuredText
-<http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html>`_.
+<https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`_.
diff --git a/tests/samples/ns1-pkg/EG_README.rst b/tests/samples/ns1-pkg/EG_README.rst
index a742974e..0d5e81c1 100644
--- a/tests/samples/ns1-pkg/EG_README.rst
+++ b/tests/samples/ns1-pkg/EG_README.rst
@@ -1,4 +1,4 @@
 This is an example long description for tests to load.
 
 This file is `valid reStructuredText
-<http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html>`_.
+<https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`_.
diff --git a/tests/samples/ns1-pkg2/EG_README.rst b/tests/samples/ns1-pkg2/EG_README.rst
index a742974e..0d5e81c1 100644
--- a/tests/samples/ns1-pkg2/EG_README.rst
+++ b/tests/samples/ns1-pkg2/EG_README.rst
@@ -1,4 +1,4 @@
 This is an example long description for tests to load.
 
 This file is `valid reStructuredText
-<http://docutils.sourceforge.net/docs/ref/rst/restructuredtext.html>`_.
+<https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html>`_.