diff --git a/Readme.md b/Readme.md
index 01dbe7d0638..22d3f227dea 100644
--- a/Readme.md
+++ b/Readme.md
@@ -1,3 +1,9 @@
+# Invitation to the ESPResSo Summer School 2022
+
+[![CECAM Flagship School registration link](https://img.shields.io/badge/CECAM%20Flagship%20School-Register%20Now-blue?style=for-the-badge)](https://www.cecam.org/workshop-details/1146)
+
+The summer school "Simulating the dynamics of soft matter with ESPResSo, PyStencils and LbmPy" will take place on October 10-14, 2022, in Stuttgart. Registration is now open on [CECAM](https://www.cecam.org/workshop-details/1146).
+
 # ESPResSo
 
 [![GitLab CI](https://gitlab.icp.uni-stuttgart.de/espressomd/espresso/badges/python/pipeline.svg)](https://gitlab.icp.uni-stuttgart.de/espressomd/espresso/commits/python)
@@ -56,7 +62,7 @@ walk you through the basic usage of ESPResSo. Advanced simulation
 methods are extensively documented, with examples and links to the
 relevant literature. Additional resources such as tutorials and
 doxygen documentation can be found on https://espressomd.github.io.
-The official website is http://espressomd.org/wordpress/.
+The official website is https://espressomd.org/wordpress/.
 
 ## Installation
 
@@ -74,7 +80,7 @@ to use 4.1.4.
 ### Join the community
 
 Please consider subscribing to our
-[mailing list](http://espressomd.org/wordpress/community-and-support/mailing-lists/)
+[mailing list](https://espressomd.org/wordpress/community-and-support/mailing-lists/)
 if you're actively using ESPResSo, as we occasionally need community
 feedback when making decisions on the future of specific features in
 upcoming releases. You'll also get notifications on bugfix releases.
@@ -83,7 +89,7 @@ upcoming releases. You'll also get notifications on bugfix releases.
 
 If you use ESPResSo to publish scientific results, we would ask you to
 acknowledge this usage by mentioning the software with its version number and
-[citing the relevant papers](http://espressomd.org/wordpress/about/please-cite-us/).
+[citing the relevant papers](https://espressomd.org/wordpress/about/please-cite-us/).
 A number of algorithms in ESPResSo are fairly advanced and unique to ESPResSo.
 The authors of these contributions kindly ask you to cite the relevant
 publications, as indicated in the documentation. For detailed instructions, see
diff --git a/doc/sphinx/conf.py.in b/doc/sphinx/conf.py.in
index 50b681bc2f3..641a1dffccd 100644
--- a/doc/sphinx/conf.py.in
+++ b/doc/sphinx/conf.py.in
@@ -268,7 +268,7 @@ def setup(app):
 
 # -- Options for Cython ---------------------------------------------------
 
-# see http://opendreamkit.org/2017/06/09/CythonSphinx/ why this is needed
+# see https://opendreamkit.org/2017/06/09/CythonSphinx/ why this is needed
 def isfunction(obj):
     return hasattr(type(obj), "__code__")
 
diff --git a/doc/sphinx/introduction.rst b/doc/sphinx/introduction.rst
index af6a22a3b3d..a89e174c202 100644
--- a/doc/sphinx/introduction.rst
+++ b/doc/sphinx/introduction.rst
@@ -548,7 +548,7 @@ our policies on :ref:`bug reports <Contributing>` and
 Releases from 4.0 onward can be found on
 `GitHub <https://github.com/espressomd/espresso/releases>`_.
 Older releases from 2.1 to 3.3 can be found in
-`GNU Savannah <http://download.savannah.gnu.org/releases/espressomd/>`_.
+`GNU Savannah <https://download.savannah.gnu.org/releases/espressomd/>`_.
 See our policy on :ref:`API backward compatibility
 <Intended interface compatibility between ESPResSo versions>`
 if you need more details.