diff --git a/qubesmanager/settings.py b/qubesmanager/settings.py
index 69bf3e8..858d58a 100644
--- a/qubesmanager/settings.py
+++ b/qubesmanager/settings.py
@@ -463,6 +463,13 @@ class VMSettingsWindow(Ui_SettingsDialog, QDialog):
             self.dmm_warning_adv.hide()
             self.dmm_warning_dev.hide()
 
+        if self.vm.is_running():
+            self.dev_list.setEnabled(False)
+            self.turn_off_vm_to_modify_devs.setVisible(True)
+        else:
+            self.dev_list.setEnabled(True)
+            self.turn_off_vm_to_modify_devs.setVisible(False)
+
 
     def __apply_devices_tab__(self):
         sth_changed = False
diff --git a/settingsdlg.ui b/settingsdlg.ui
index c485c2a..3946024 100644
--- a/settingsdlg.ui
+++ b/settingsdlg.ui
@@ -29,7 +29,7 @@
         <locale language="English" country="UnitedStates"/>
        </property>
        <property name="currentIndex">
-        <number>4</number>
+        <number>3</number>
        </property>
        <widget class="QWidget" name="basic_tab">
         <property name="locale">
@@ -757,8 +757,8 @@
         <attribute name="title">
          <string>Devices</string>
         </attribute>
-        <layout class="QGridLayout" name="gridLayout_6">
-         <item row="0" column="0">
+        <layout class="QVBoxLayout" name="verticalLayout_3">
+         <item>
           <layout class="QVBoxLayout" name="devices_layout">
            <item>
             <widget class="QLabel" name="dmm_warning_dev">
@@ -777,6 +777,20 @@
              </property>
             </widget>
            </item>
+           <item>
+            <widget class="QLabel" name="turn_off_vm_to_modify_devs">
+             <property name="font">
+              <font>
+               <weight>75</weight>
+               <italic>true</italic>
+               <bold>true</bold>
+              </font>
+             </property>
+             <property name="text">
+              <string>To modify PCI devices you have to turn off the VM.</string>
+             </property>
+            </widget>
+           </item>
           </layout>
          </item>
         </layout>