diff --git a/src/calibre/gui2/preferences/search.py b/src/calibre/gui2/preferences/search.py
index 936d1a2e9e..7542f4afdd 100644
--- a/src/calibre/gui2/preferences/search.py
+++ b/src/calibre/gui2/preferences/search.py
@@ -13,6 +13,7 @@ from calibre.gui2.preferences.search_ui import Ui_Form
 from calibre.gui2 import config, error_dialog
 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):
 
@@ -223,6 +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.set_highlight_only_button_icon()
         if self.muc_changed:
             gui.tags_view.recount()
diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index 99923657d5..d18a10dbfd 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -118,10 +118,15 @@ class MetadataBackup(Thread): # {{{
 
 # }}}
 
+
+### Global utility function for get_match here and in gui2/library.py
 # This is a global for performance
 pref_use_primary_find_in_search = False
 
-### Global utility function for get_match here and in gui2/library.py
+def set_use_primary_find_in_search(toWhat):
+    global pref_use_primary_find_in_search
+    pref_use_primary_find_in_search = toWhat
+
 CONTAINS_MATCH = 0
 EQUALS_MATCH   = 1
 REGEXP_MATCH   = 2
@@ -252,6 +257,9 @@ class ResultCache(SearchQueryParser): # {{{
         SearchQueryParser.__init__(self, self.all_search_locations, optimize=True)
         self.build_date_relop_dict()
         self.build_numeric_relop_dict()
+        # Do this here so the var get updated when a library changes
+        global pref_use_primary_find_in_search
+        pref_use_primary_find_in_search = prefs['use_primary_find_in_search']
 
     def break_cycles(self):
         self._data = self.field_metadata = self.FIELD_MAP = \
@@ -617,9 +625,6 @@ class ResultCache(SearchQueryParser): # {{{
 
     def get_matches(self, location, query, candidates=None,
             allow_recursion=True):
-        global pref_use_primary_find_in_search
-        pref_use_primary_find_in_search = prefs['use_primary_find_in_search']
-
         matches = set([])
         if candidates is None:
             candidates = self.universal_set()