--- a/eric6/Preferences/ConfigurationPages/EditorSpellCheckingPage.ui	Wed Oct 23 19:57:49 2019 +0200
+++ b/eric6/Preferences/ConfigurationPages/EditorSpellCheckingPage.ui	Wed Oct 23 19:59:23 2019 +0200
@@ -112,14 +112,28 @@
         </property>
         <layout class="QVBoxLayout" name="verticalLayout">
          <item>
-          <widget class="QCheckBox" name="stringsOnlyCheckBox">
-           <property name="toolTip">
-            <string>Select to check strings only</string>
-           </property>
-           <property name="text">
-            <string>Spell check strings only</string>
-           </property>
-          </widget>
+          <layout class="QHBoxLayout" name="horizontalLayout_4">
+           <item>
+            <widget class="QCheckBox" name="stringsOnlyCheckBox">
+             <property name="toolTip">
+              <string>Select to check strings only</string>
+             </property>
+             <property name="text">
+              <string>Spell check strings only</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QCheckBox" name="fullCheckUnknownCheckBox">
+             <property name="toolTip">
+              <string>Select to perform a complete check of files without extension</string>
+             </property>
+             <property name="text">
+              <string>Spell check unknown files</string>
+             </property>
+            </widget>
+           </item>
+          </layout>
          </item>
          <item>
           <layout class="QHBoxLayout" name="horizontalLayout">
@@ -153,7 +167,7 @@
             </widget>
            </item>
            <item>
-            <widget class="QLCDNumber" name="lCDNumber">
+            <widget class="QLCDNumber" name="lcdNumber">
              <property name="toolTip">
               <string>Displays the minimum size of words to be checked</string>
              </property>
@@ -170,6 +184,28 @@
            </item>
           </layout>
          </item>
+         <item>
+          <layout class="QHBoxLayout" name="horizontalLayout_2">
+           <item>
+            <widget class="QLabel" name="label_8">
+             <property name="text">
+              <string>Textfiles:</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="E5ClearableLineEdit" name="spellCheckTextFilesLineEdit">
+             <property name="toolTip">
+              <string>Enter the file extensions of pure text files (separated by a space)</string>
+             </property>
+             <property name="whatsThis">
+              <string>&lt;b&gt;Textfiles&lt;/b&gt;
+&lt;p&gt;Enter the file extension of pure text files. The complete contents of files with these extensions will be checked.&lt;/p&gt;</string>
+             </property>
+            </widget>
+           </item>
+          </layout>
+         </item>
         </layout>
        </widget>
       </item>
@@ -365,12 +401,19 @@
    <header>E5Gui/E5PathPicker.h</header>
    <container>1</container>
   </customwidget>
+  <customwidget>
+   <class>E5ClearableLineEdit</class>
+   <extends>QLineEdit</extends>
+   <header>E5Gui/E5LineEdit.h</header>
+  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>checkingEnabledCheckBox</tabstop>
   <tabstop>defaultLanguageCombo</tabstop>
   <tabstop>stringsOnlyCheckBox</tabstop>
+  <tabstop>fullCheckUnknownCheckBox</tabstop>
   <tabstop>minimumWordSizeSlider</tabstop>
+  <tabstop>spellCheckTextFilesLineEdit</tabstop>
   <tabstop>spellingMarkerButton</tabstop>
   <tabstop>pwlPicker</tabstop>
   <tabstop>pelPicker</tabstop>
@@ -382,7 +425,7 @@
   <connection>
    <sender>minimumWordSizeSlider</sender>
    <signal>valueChanged(int)</signal>
-   <receiver>lCDNumber</receiver>
+   <receiver>lcdNumber</receiver>
    <slot>display(int)</slot>
    <hints>
     <hint type="sourcelabel">