diff --git a/data/cosin.toml b/data/cosin.toml
index aee084e..a72bc55 100644
--- a/data/cosin.toml
+++ b/data/cosin.toml
@@ -58,6 +58,10 @@ streaming_main_url = "https://streaming.cosin.ch"
 irc_server = "ircs://irc.chaostreff.ch:6601/"
 irc_channel = "#cosin"
 
+matrix_server = "fairydust.space"
+matrix_room = "#cosin"
+matrix_client = "https://chat.fairydust.space/#/room/"
+
 mastodon_server = "https://chaos.social/"
 mastodon_handle = "@CoSin"
 
diff --git a/layouts/partials/site-sidebar.de.html b/layouts/partials/site-sidebar.de.html
index 9572469..0332528 100644
--- a/layouts/partials/site-sidebar.de.html
+++ b/layouts/partials/site-sidebar.de.html
@@ -65,6 +65,9 @@ Offen bis {{ .cfp_end_date_day }}. {{ i18n .cfp_end_date_month }} {{ .date_year
 <p><strong>IRC:</strong> <a href="{{ .irc_server | safeURL }}{{ .irc_channel }}">{{ .irc_channel }}</a></p>
 
 
+<p><strong>Matrix:</strong> <a href="{{ .matrix_client | safeURL }}{{ urlquery .matrix_room }}:{{ .matrix_server }}">{{ .matrix_room }}:{{ .matrix_server }}</a></p>
+
+
 <p><strong>Mastodon:</strong> <a rel="me" href="{{ .mastodon_server | safeURL }}{{ .mastodon_handle }}">{{ .mastodon_handle }}</a></p>
 {{ end }}
 
diff --git a/layouts/partials/site-sidebar.en.html b/layouts/partials/site-sidebar.en.html
index 8b3f07e..bafd126 100644
--- a/layouts/partials/site-sidebar.en.html
+++ b/layouts/partials/site-sidebar.en.html
@@ -65,6 +65,9 @@ Open until {{ .cfp_end_date_day }}. {{ i18n .cfp_end_date_month }} {{ .date_year
 <p><strong>IRC:</strong> <a href="{{ .irc_server | safeURL }}{{ .irc_channel }}">{{ .irc_channel }}</a></p>
 
 
+<p><strong>Matrix:</strong> <a href="{{ .matrix_client | safeURL }}{{ urlquery .matrix_room }}:{{ .matrix_server }}">{{ .matrix_room }}:{{ .matrix_server }}</a></p>
+
+
 <p><strong>Mastodon:</strong> <a rel="me" href="{{ .mastodon_server | safeURL }}{{ .mastodon_handle }}">{{ .mastodon_handle }}</a></p>
 {{ end }}
 
diff --git a/layouts/partials/site-sidebar.fr.html b/layouts/partials/site-sidebar.fr.html
index 21f0776..5fb30c3 100644
--- a/layouts/partials/site-sidebar.fr.html
+++ b/layouts/partials/site-sidebar.fr.html
@@ -65,6 +65,9 @@ Offen bis {{ .cfp_end_date_day }}. {{ i18n .cfp_end_date_month }} {{ .date_year
 <p><strong>IRC:</strong> <a href="{{ .irc_server | safeURL }}{{ .irc_channel }}">{{ .irc_channel }}</a></p>
 
 
+<p><strong>Matrix:</strong> <a href="{{ .matrix_client | safeURL }}{{ urlquery .matrix_room }}:{{ .matrix_server }}">{{ .matrix_room }}:{{ .matrix_server }}</a></p>
+
+
 <p><strong>Mastodon:</strong> <a rel="me" href="{{ .mastodon_server | safeURL }}{{ .mastodon_handle }}">{{ .mastodon_handle }}</a></p>
 {{ end }}
 
diff --git a/layouts/partials/site-sidebar.it.html b/layouts/partials/site-sidebar.it.html
index c7179aa..9c9a28e 100644
--- a/layouts/partials/site-sidebar.it.html
+++ b/layouts/partials/site-sidebar.it.html
@@ -65,6 +65,9 @@ Offen bis {{ .cfp_end_date_day }}. {{ i18n .cfp_end_date_month }} {{ .date_year
 <p><strong>IRC:</strong> <a href="{{ .irc_server | safeURL }}{{ .irc_channel }}">{{ .irc_channel }}</a></p>
 
 
+<p><strong>Matrix:</strong> <a href="{{ .matrix_client | safeURL }}{{ urlquery .matrix_room }}:{{ .matrix_server }}">{{ .matrix_room }}:{{ .matrix_server }}</a></p>
+
+
 <p><strong>Mastodon:</strong> <a rel="me" href="{{ .mastodon_server | safeURL }}{{ .mastodon_handle }}">{{ .mastodon_handle }}</a></p>
 {{ end }}