diff --git a/plugins/calendar/calendar_ui.js b/plugins/calendar/calendar_ui.js
index 25a192c0..ce5db2bd 100644
--- a/plugins/calendar/calendar_ui.js
+++ b/plugins/calendar/calendar_ui.js
@@ -3490,8 +3490,7 @@ function rcube_calendar_ui(settings)
     this.dialog_resize = function(id, height, width)
     {
       var win = $(window), w = win.width(), h = win.height();
-      $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) })
-        .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
+      $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) });
     };
 
     // adjust calendar view size
diff --git a/plugins/kolab_files/kolab_files.js b/plugins/kolab_files/kolab_files.js
index 620a7ed2..1bc00217 100644
--- a/plugins/kolab_files/kolab_files.js
+++ b/plugins/kolab_files/kolab_files.js
@@ -1296,7 +1296,6 @@ function manticore_close()
       dialogClass: 'popupmessage error',
       title: rcmail.gettext('kolab_files.sessionterminatedtitle'),
       close: function() { window.close(); },
-      position: ['center', 'center'],
       width: 420,
       minHeight: 90
     }).show();
diff --git a/plugins/kolab_notes/notes.js b/plugins/kolab_notes/notes.js
index be9097d7..cd52c3bf 100644
--- a/plugins/kolab_notes/notes.js
+++ b/plugins/kolab_notes/notes.js
@@ -521,8 +521,7 @@ function rcube_kolab_notes_ui(settings)
                 // resize and reposition dialog window
                 form = $('#noteslistpropform');
                 var win = $(window), w = win.width(), h = win.height();
-                $dialog.dialog('option', { height: Math.min(h-20, form.height()+130), width: Math.min(w-20, form.width()+50) })
-                    .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
+                $dialog.dialog('option', { height: Math.min(h-20, form.height()+130), width: Math.min(w-20, form.width()+50) });
 
                 name = $('#noteslist-name').prop('disabled', !has_permission(list, 'a')).val(list.editname || list.name);
                 name.select();
diff --git a/plugins/libkolab/js/audittrail.js b/plugins/libkolab/js/audittrail.js
index 84fdf61b..5ec6d091 100644
--- a/plugins/libkolab/js/audittrail.js
+++ b/plugins/libkolab/js/audittrail.js
@@ -218,8 +218,7 @@ libkolab_audittrail.render_changelog = function(data, object, folder)
 libkolab_audittrail.dialog_resize = function(id, height, width)
 {
     var win = $(window), w = win.width(), h = win.height();
-        $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) })
-            .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
+    $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) });
 };
 
 
diff --git a/plugins/tasklist/tasklist.js b/plugins/tasklist/tasklist.js
index 4b02faad..15874559 100644
--- a/plugins/tasklist/tasklist.js
+++ b/plugins/tasklist/tasklist.js
@@ -3334,8 +3334,7 @@ function rcube_tasklist_ui(settings)
     this.dialog_resize = function(id, height, width)
     {
         var win = $(window), w = win.width(), h = win.height();
-            $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) })
-                .dialog('option', 'position', ['center', 'center']);  // only works in a separate call (!?)
+        $(id).dialog('option', { height: Math.min(h-20, height+130), width: Math.min(w-20, width+50) });
     };
 
     /**