diff --git a/.github/workflows/rssguard.yml b/.github/workflows/rssguard.yml
index 375cfdff2..f7fcd3f77 100644
--- a/.github/workflows/rssguard.yml
+++ b/.github/workflows/rssguard.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: "${{ matrix.os }}"
     strategy:
       matrix:
-        os: [windows-2019, ubuntu-16.04, macos-10.15]
+        os: [windows-2019, ubuntu-18.04, macos-10.15]
         use_webengine: ["true", "false"]
         include:
           - os: windows-2019
diff --git a/resources/desktop/com.github.rssguard.appdata.xml b/resources/desktop/com.github.rssguard.appdata.xml
index ff95866c2..1328daa79 100644
--- a/resources/desktop/com.github.rssguard.appdata.xml
+++ b/resources/desktop/com.github.rssguard.appdata.xml
@@ -26,7 +26,7 @@
   <url type="donation">https://github.com/sponsors/martinrotter</url>
   <content_rating type="oars-1.1" />
   <releases>
-    <release version="4.0.0" date="2021-09-07"/>
+    <release version="4.0.0" date="2021-09-08"/>
   </releases>
   <content_rating type="oars-1.0">
     <content_attribute id="violence-cartoon">none</content_attribute>
diff --git a/resources/scripts/github-actions/build-linux-mac.sh b/resources/scripts/github-actions/build-linux-mac.sh
index c4e38bcb6..16cbc773d 100755
--- a/resources/scripts/github-actions/build-linux-mac.sh
+++ b/resources/scripts/github-actions/build-linux-mac.sh
@@ -16,19 +16,20 @@ echo "OS: $os; WebEngine: $webengine"
 
 # Prepare environment.
 if [ $is_linux = true ]; then
-  sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
-  sudo add-apt-repository ppa:beineri/opt-qt-5.14.2-xenial -y
-
+  #sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y
+  sudo add-apt-repository ppa:beineri/opt-qt-5.15.2-bionic -y
   sudo apt-get update
-  sudo apt-get -y install gcc-7 g++-7 qt514tools qt514base qt514webengine qt514svg qt514multimedia 
+
+  #sudo apt-get -y install gcc-7 g++-7
+  sudo apt-get -y install qt515tools qt515base qt515webengine qt515svg qt515multimedia 
   sudo apt-get -y install openssl libssl-dev libgl1-mesa-dev 
 
-  sudo update-alternatives --remove-all gcc 
-  sudo update-alternatives --remove-all g++
-  sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 50
-  sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 50
+  #sudo update-alternatives --remove-all gcc 
+  #sudo update-alternatives --remove-all g++
+  #sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-7 50
+  #sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-7 50
   
-  source /opt/qt514/bin/qt514-env.sh
+  source /opt/qt515/bin/qt515-env.sh
 else
   pip3 install aqtinstall
   
@@ -65,6 +66,7 @@ if [ $is_linux = true ]; then
   # Create AppImage.
   unset QTDIR; unset QT_PLUGIN_PATH ; unset LD_LIBRARY_PATH
   ./linuxdeployqt-continuous-x86_64.AppImage "./AppDir/usr/share/applications/com.github.rssguard.desktop" -bundle-non-qt-libs -no-translations
+  ./linuxdeployqt-continuous-x86_64.AppImage "./AppDir/usr/share/applications/com.github.rssguard.desktop" -bundle-non-qt-libs -no-translations
 
   if [[ "$webengine" == "true" ]]; then
     # Copy some NSS3 files to prevent WebEngine crashes.