diff --git a/lib/os/class.ISPConfigDebianOS.inc.php b/lib/os/class.ISPConfigDebianOS.inc.php
index 12bec231a51e2673d225c5df26b72398cb27b622..65b9031c5f8d318983d101c3b71589668b1c4f31 100644
--- a/lib/os/class.ISPConfigDebianOS.inc.php
+++ b/lib/os/class.ISPConfigDebianOS.inc.php
@@ -281,6 +281,20 @@ class ISPConfigDebianOS extends ISPConfigBaseOS {
 		}
 	}
 
+	protected function installUnattendedUpgrades() {
+		ISPConfigLog::info('Installing UnattendedUpgrades', true);
+
+		$packages = array(
+			'unattended-upgrades',
+			'apt-listchanges'
+		);
+		$this->installPackages($packages);
+
+		// Enable UnattendUpgrades to run every day
+		$unattendedupgrades = 'APT::Periodic::Update-Package-Lists "1";' . "\n" . 'APT::Periodic::Unattended-Upgrade "1";';
+		file_put_contents('/etc/apt/apt.conf.d/20auto-upgrades', $unattendedupgrades);
+	}
+
 	protected function shallCompileJailkit() {
 		return true;
 	}
@@ -389,22 +403,6 @@ mailman-unsubscribe:  "|/var/lib/mailman/mail/mailman unsubscribe mailman"';
 		return $listpw;
 	}
 
-	protected function installUnattendedUpgrades() {
-		if(ISPConfig::shallInstall('unattended-upgrades')) {
-			ISPConfigLog::info('Installing UnattendedUpgrades', true);
-
-			$packages = array(
-				'unattended-upgrades',
-				'apt-listchanges'
-			);
-			$this->installPackages($packages);
-
-			// Enable UnattendUpgrades to run every day
-			$unattendedupgrades = 'APT::Periodic::Update-Package-Lists "1";' . "\n" . 'APT::Periodic::Unattended-Upgrade "1";';
-			file_put_contents('/etc/apt/apt.conf.d/20auto-upgrades', $unattendedupgrades);
-		}
-	}
-
 	protected function installPackages($packages) {
 		if(is_string($packages)) {
 			$packages = array($packages);
@@ -1066,6 +1064,10 @@ mailman-unsubscribe:  "|/var/lib/mailman/mail/mailman unsubscribe mailman"';
 
 		$this->fixDbconfigCommon();
 
+		if(ISPConfig::shallInstall('unattended-upgrades')) {
+			$this->installUnattendedUpgrades();
+		}
+
 		if(ISPConfig::shallInstall('mail') && ISPConfig::shallInstall('roundcube')) {
 			ISPConfigLog::info('Installing roundcube.', true);
 
diff --git a/lib/os/class.ISPConfigUbuntuOS.inc.php b/lib/os/class.ISPConfigUbuntuOS.inc.php
index ba05acbcd2d1ff574a3c793fbe7af3c2f0ba72bc..5d838d2120a0b32d01cdfa59db2a30a6ae156881 100644
--- a/lib/os/class.ISPConfigUbuntuOS.inc.php
+++ b/lib/os/class.ISPConfigUbuntuOS.inc.php
@@ -103,8 +103,8 @@ maxretry = 3';
 	}
 
 	protected function installUnattendedUpgrades() {
-		if(ISPConfig::shallInstall('unattended-upgrades')) {
 			ISPConfigLog::info('Installing UnattendedUpgrades', true);
+
 			$packages = array(
 				'unattended-upgrades',
 				'apt-listchanges'
@@ -112,13 +112,7 @@ maxretry = 3';
 			$this->installPackages($packages);
 
 			// Enable UnattendUpgrades to run every day
-			$unattendedupgrades = 'APT::Periodic::Update-Package-Lists \"1\";' . "\n" . 'APT::Periodic::Unattended-Upgrade \"1\";';
+			$unattendedupgrades = 'APT::Periodic::Update-Package-Lists "1";' . "\n" . 'APT::Periodic::Unattended-Upgrade "1";';
 			file_put_contents('/etc/apt/apt.conf.d/20auto-upgrades', $unattendedupgrades);
-
-			// Enable normal updates
-			$replacements = array(
-				'/^\/\/\s*"\$\{distro_id\}:\$\{distro_codename\}\-updates";/m' => '      \"${distro_id}:${distro_codename}-updates\";'
-			);
-			$result = $this->replaceContents('/etc/apt/apt.conf.d/50unattended-upgrades', $replacements);
-		}
 	}
+}