diff --git a/src/calibre/gui2/preferences/__init__.py b/src/calibre/gui2/preferences/__init__.py
index 98e0285464..3169cafffa 100644
--- a/src/calibre/gui2/preferences/__init__.py
+++ b/src/calibre/gui2/preferences/__init__.py
@@ -8,7 +8,7 @@ __docformat__ = 'restructuredtext en'
 import textwrap
 
 from PyQt5.Qt import (QWidget, pyqtSignal, QCheckBox, QAbstractSpinBox,
-    QLineEdit, QComboBox, Qt, QIcon, QDialog, QVBoxLayout,
+    QLineEdit, QComboBox, Qt, QIcon, QDialog, QVBoxLayout, QRadioButton,
     QDialogButtonBox)
 
 from calibre.customize.ui import preferences_plugins
@@ -101,6 +101,9 @@ class Setting(object):
         if isinstance(self.gui_obj, QCheckBox):
             self.datatype = 'bool'
             self.gui_obj.stateChanged.connect(self.changed)
+        elif isinstance(self.gui_obj, QRadioButton):
+            self.datatype = 'bool'
+            self.gui_obj.toggled.connect(self.changed)
         elif isinstance(self.gui_obj, QAbstractSpinBox):
             self.datatype = 'number'
             self.gui_obj.valueChanged.connect(self.changed)
diff --git a/src/calibre/gui2/preferences/search.py b/src/calibre/gui2/preferences/search.py
index 5e879a8081..2cff7a9fca 100644
--- a/src/calibre/gui2/preferences/search.py
+++ b/src/calibre/gui2/preferences/search.py
@@ -7,13 +7,11 @@ __docformat__ = 'restructuredtext en'
 
 from PyQt5.Qt import QApplication
 
-from calibre.gui2.preferences import ConfigWidgetBase, test_widget, \
-        CommaSeparatedList, AbortCommit
+from calibre.gui2.preferences import ConfigWidgetBase, test_widget, CommaSeparatedList
 from calibre.gui2.preferences.search_ui import Ui_Form
 from calibre.gui2 import config, error_dialog, gprefs
 from calibre.utils.config import prefs
 from calibre.utils.icu import sort_key
-from calibre.library.caches import set_use_primary_find_in_search
 
 class ConfigWidget(ConfigWidgetBase, Ui_Form):
 
@@ -102,12 +100,6 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.muc_changed = False
         self.opt_grouped_search_make_user_categories.lineEdit().editingFinished.connect(
                                                         self.muc_box_changed)
-        self.opt_case_sensitive.toggled.connect(self.case_sensitive_toggled)
-        self.case_sensitive_toggled()
-
-    def case_sensitive_toggled(self):
-        if self.opt_case_sensitive.isChecked():
-            self.opt_use_primary_find_in_search.setChecked(False)
 
     def set_similar_fields(self, initial=False):
         self.set_similar('similar_authors_search_key', initial=initial)
@@ -218,11 +210,6 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         self.gst_value.blockSignals(False)
 
     def commit(self):
-        if self.opt_case_sensitive.isChecked() and self.opt_use_primary_find_in_search.isChecked():
-            error_dialog(self, _('Incompatible options'), _(
-                'The option to have un-accented characters match accented characters has no effect'
-                ' if you also turn on case-sensitive searching. So only turn on one of those options'), show=True)
-            raise AbortCommit()
         if self.gst_changed:
             self.db.new_api.set_pref('grouped_search_terms', self.gst)
             self.db.field_metadata.add_grouped_search_terms(self.gst)
@@ -237,7 +224,7 @@ class ConfigWidget(ConfigWidgetBase, Ui_Form):
         return ConfigWidgetBase.commit(self)
 
     def refresh_gui(self, gui):
-        set_use_primary_find_in_search(prefs['use_primary_find_in_search'])
+        gui.current_db.new_api.clear_caches()  # Clear the search cache
         gui.set_highlight_only_button_icon()
         if self.muc_changed:
             gui.tags_view.recount()
diff --git a/src/calibre/gui2/preferences/search.ui b/src/calibre/gui2/preferences/search.ui
index c00612777a..69a5e3029e 100644
--- a/src/calibre/gui2/preferences/search.ui
+++ b/src/calibre/gui2/preferences/search.ui
@@ -307,14 +307,14 @@ to be shown as user categories</string>
     </widget>
    </item>
    <item row="3" column="0">
-    <widget class="QCheckBox" name="opt_case_sensitive">
+    <widget class="QRadioButton" name="opt_case_sensitive">
      <property name="text">
       <string>Case sensitive searching</string>
      </property>
     </widget>
    </item>
    <item row="3" column="1">
-    <widget class="QCheckBox" name="opt_use_primary_find_in_search">
+    <widget class="QRadioButton" name="opt_use_primary_find_in_search">
      <property name="text">
       <string>Unaccented characters match accented characters</string>
      </property>
diff --git a/src/calibre/utils/config_base.py b/src/calibre/utils/config_base.py
index bfc8d7b92f..8baf932b94 100644
--- a/src/calibre/utils/config_base.py
+++ b/src/calibre/utils/config_base.py
@@ -440,7 +440,8 @@ def create_global_prefs(conf_obj=None):
                    'libraries. Note that this option will have no effect if you turn '
                    'on case-sensitive searching')%u'\xf1')
     c.add_opt('case_sensitive', default=False, help=_(
-        'Make searches case-sensitive'))
+        'Make searches case-sensitive. Note that turning on case-sensitive searches disables matching of '
+        'accented characters by their unaccented versions.'))
 
     c.add_opt('migrated', default=False, help='For Internal use. Don\'t modify.')
     return c