diff --git a/CHANGELOG b/CHANGELOG
index 9bfb6d7e2..9509ba2ac 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -14,6 +14,7 @@ CHANGELOG Roundcube Webmail
 - Enigma: Fix so using list checkbox selection does not load the key preview frame
 - Enigma: Fix generation of key pairs for identities with IDN domains (#7181)
 - Enigma: Display IDN domains of key users and identities in UTF8
+- Managesieve: Fix bug where it wasn't possible to save flag actions (#7188)
 - Markasjunk: Fix bug where marking as spam/ham didn't work on moving messages with drag-and-drop (#7137)
 - Password: Make chpass-wrapper.py Python 3 compatible (#7135)
 - Elastic: Fix disappearing sidebar in mail compose after clicking Mail button
diff --git a/plugins/managesieve/Changelog b/plugins/managesieve/Changelog
index 69a0fd88b..d39181cea 100644
--- a/plugins/managesieve/Changelog
+++ b/plugins/managesieve/Changelog
@@ -2,6 +2,7 @@
 - Replace "Filter disabled" with "Filter enabled" (#7028)
 - Fix so modifier type select wasn't hidden after hiding modifier select on header change
 - Fix filter selection after removing a first filter (#7079)
+- Fix bug where it wasn't possible to save flag actions (#7188)
 
 * version 9.3 [2019-04-21]
 -----------------------------------------------------------
diff --git a/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php b/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
index 25056ff03..72afcd069 100644
--- a/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
+++ b/plugins/managesieve/lib/Roundcube/rcube_sieve_engine.php
@@ -1084,16 +1084,12 @@ class rcube_sieve_engine
                 case 'addflag':
                 case 'setflag':
                 case 'removeflag':
-                    $_target = array();
-                    if (empty($flags[$idx])) {
-                        $this->errors['actions'][$i]['target'] = $this->plugin->gettext('noflagset');
-                    }
-                    else {
-                        foreach ($flags[$idx] as $flag) {
-                            $_target[] = $this->strip_value($flag);
-                        }
+                    $this->form['actions'][$i]['target'] = $this->strip_value($flags[$idx]);
+
+                    if (empty($this->form['actions'][$i]['target'])) {
+                        $this->errors['actions'][$i]['flag'] = $this->plugin->gettext('noflagset');
                     }
-                    $this->form['actions'][$i]['target'] = $_target;
+
                     break;
 
                 case 'addheader':
@@ -2316,7 +2312,7 @@ class rcube_sieve_engine
         }
 
         $flout .= $this->list_input($id, 'action_flags', $custom_flags, true,
-            $this->error_class($id, 'action', 'flags', 'action_flags'));
+            $this->error_class($id, 'action', 'flag', 'action_flags_flag'), null, false, "action_flags_flag{$id}");
 
         $out .= html::div(array(
                 'id'    => 'action_flags' . $id,
@@ -2578,7 +2574,7 @@ class rcube_sieve_engine
         return $trim ? trim($str) : $str;
     }
 
-    protected function error_class($id, $type, $target, $elem_prefix='')
+    protected function error_class($id, $type, $target, $elem_prefix = '')
     {
         // TODO: tooltips
         if (($type == 'test' && ($str = $this->errors['tests'][$id][$target])) ||
@@ -2610,7 +2606,7 @@ class rcube_sieve_engine
         $this->rc->output->add_script($script, 'docready');
     }
 
-    protected function list_input($id, $name, $value, $enabled, $class, $size = null, $hidden = false)
+    protected function list_input($id, $name, $value, $enabled, $class, $size = null, $hidden = false, $elem_id = null)
     {
         $value = (array) $value;
         $value = array_map(array('rcube', 'Q'), $value);
@@ -2621,7 +2617,7 @@ class rcube_sieve_engine
                 'data-size' => $size,
                 'data-hidden' => $hidden ?: null,
                 'name'      => '_' . $name . '[' . $id . ']',
-                'id'        => $name.$id,
+                'id'        => $elem_id ?: ($name.$id),
                 'disabled'  => !$enabled,
                 'class'     => $class,
                 'style'     => 'display:none',
diff --git a/plugins/managesieve/localization/en_US.inc b/plugins/managesieve/localization/en_US.inc
index a5c6d2702..4758bec72 100644
--- a/plugins/managesieve/localization/en_US.inc
+++ b/plugins/managesieve/localization/en_US.inc
@@ -276,3 +276,4 @@ $messages['emptyvacationbody'] = 'Body of vacation message is required!';
 $messages['duplicate.conflict.err'] = 'Both header and unique identifier are not allowed.';
 $messages['disabledaction'] = 'Action not permitted.';
 $messages['lastindexempty'] = 'Index is required when counting from end';
+$messages['noflagset'] = 'At least one flag must be selected.';
diff --git a/skins/elastic/styles/widgets/forms.less b/skins/elastic/styles/widgets/forms.less
index 3b3892518..e8bebcf89 100644
--- a/skins/elastic/styles/widgets/forms.less
+++ b/skins/elastic/styles/widgets/forms.less
@@ -833,6 +833,7 @@ html.ms .propform {
 
         & > .invalid-feedback {
             display: inline-block;
+            line-height: 1.5;
         }
     }
 }