diff --git a/install/dist/lib/opensuse.lib.php b/install/dist/lib/opensuse.lib.php
index 462a69499880e6776b9e693d57ac6d308d8495f0..5c0af8ffa0246567ed16532d81553ac146b0fe67 100644
--- a/install/dist/lib/opensuse.lib.php
+++ b/install/dist/lib/opensuse.lib.php
@@ -529,7 +529,9 @@ class installer_dist extends installer_base {
 		unset($content);
 
 		// Add the clamav user to the vscan group
-		exec('groupmod --add-user clamav vscan');
+		//exec('groupmod --add-user clamav vscan');
+		$command = 'usermod -a -G clamav vscan';
+		caselog($command." &> /dev/null", __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 
 
 	}
@@ -1051,18 +1053,22 @@ class installer_dist extends installer_base {
 		// and must be fixed as this will allow the apache user to read the ispconfig files.
 		// Later this must run as own apache server or via suexec!
 		if($conf['apache']['installed'] == true){
-			$command = 'groupmod --add-user '.$conf['apache']['user'].' ispconfig';
+			//$command = 'groupmod --add-user '.$conf['apache']['user'].' ispconfig';
+			$command = 'usermod -a -G ispconfig '.$conf['apache']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 			if(is_group('ispapps')){
-				$command = 'groupmod --add-user '.$conf['apache']['user'].' ispapps';
+				//$command = 'groupmod --add-user '.$conf['apache']['user'].' ispapps';
+				$command = 'usermod -a -G ispapps '.$conf['apache']['user'];
 				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 			}
 		}
 		if($conf['nginx']['installed'] == true){
-			$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispconfig';
+			//$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispconfig';
+			 $command = 'usermod -a -G ispconfig '.$conf['nginx']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 			if(is_group('ispapps')){
-				$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispapps';
+				//$command = 'groupmod --add-user '.$conf['nginx']['user'].' ispapps';
+				$command = 'usermod -a -G ispapps '.$conf['nginx']['user'];
 				caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 			}
 		}
diff --git a/install/lib/installer_base.lib.php b/install/lib/installer_base.lib.php
index 51d24952265f188995ccac7a4a004c47b7db2f2a..d8337d8d54f2e73bad444f6e5266b51ed060c147 100644
--- a/install/lib/installer_base.lib.php
+++ b/install/lib/installer_base.lib.php
@@ -1495,7 +1495,8 @@ class installer_base {
 			if(!is_user($apps_vhost_user)) caselog($command.' &> /dev/null 2> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 
 
-			$command = 'adduser '.$conf['apache']['user'].' '.$apps_vhost_group;
+			//$command = 'adduser '.$conf['apache']['user'].' '.$apps_vhost_group;
+			$command = 'usermod -a -G '.$apps_vhost_group.' '.$conf['apache']['user'];
 			caselog($command.' &> /dev/null', __FILE__, __LINE__, "EXECUTED: $command", "Failed to execute the command $command");
 
 			if(!@is_dir($install_dir)){