diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c4e9db..ab3230e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,5 @@
+**unreleased**
+
 **0.20.0**
 - Added the ability to sign multiple keys in a single request, thus enabling multiple users to claim a single receiver
   on receiverbook.de
diff --git a/debian/changelog b/debian/changelog
index e0c9239..fae1aca 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,7 @@
+openwebrx (0.21.0) UNRELEASED; urgency=low
+
+ -- Jakob Ketterl <jakob.ketterl@gmx.de>  Sun, 11 Oct 2020 21:12:00 +0000
+
 openwebrx (0.20.0) buster focal; urgency=low
 
   * Added the ability to sign multiple keys in a single request, thus enabling
diff --git a/htdocs/index.html b/htdocs/index.html
index 5e6f1ea..ed05093 100644
--- a/htdocs/index.html
+++ b/htdocs/index.html
@@ -45,6 +45,10 @@
     </div>
     <div id="openwebrx-panels-container">
         <div id="openwebrx-panels-container-left">
+            <div class="openwebrx-panel" data-panel-name="client-under-devel" style="width: 245px; background-color: Red;">
+                <span style="font-size: 15pt; font-weight: bold;">Under construction</span>
+                <br />We're working on the code right now, so the application might fail.
+            </div>
             <div class="openwebrx-panel" id="openwebrx-panel-digimodes" style="display: none; width: 619px;" data-panel-name="digimodes">
                 <div id="openwebrx-digimode-canvas-container">
                     <div id="openwebrx-digimode-select-channel"></div>
diff --git a/owrx/version.py b/owrx/version.py
index cd89792..5f1cab0 100644
--- a/owrx/version.py
+++ b/owrx/version.py
@@ -1,5 +1,5 @@
 from distutils.version import LooseVersion
 
-_versionstring = "0.20.0"
+_versionstring = "0.21.0-dev"
 looseversion = LooseVersion(_versionstring)
 openwebrx_version = "v{0}".format(looseversion)