diff --git a/src/calibre/gui2/ui.py b/src/calibre/gui2/ui.py
index 800eeacdc8..a725d78b07 100644
--- a/src/calibre/gui2/ui.py
+++ b/src/calibre/gui2/ui.py
@@ -464,6 +464,7 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, EmailMixin, # {{{
             self.library_view.model().refresh()
             self.library_view.model().research()
             self.tags_view.recount()
+            self.library_view.model().db.refresh_format_cache()
         elif msg.startswith('shutdown:'):
             self.quit(confirm_quit=False)
         else:
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 00ca0e39a2..87dbe3ef66 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -312,10 +312,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             load_user_template_functions(self.prefs.get('user_template_functions', []))
 
         # Load the format filename cache
-        self.format_filename_cache = defaultdict(dict)
-        for book_id, fmt, name in self.conn.get(
-                'SELECT book,format,name FROM data'):
-            self.format_filename_cache[book_id][fmt.upper() if fmt else ''] = name
+        self.refresh_format_cache()
 
         self.conn.executescript('''
         DROP TRIGGER IF EXISTS author_insert_trg;
@@ -528,6 +525,11 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         ''' Return last modified time as a UTC datetime object'''
         return utcfromtimestamp(os.stat(self.dbpath).st_mtime)
 
+    def refresh_format_cache(self):
+        self.format_filename_cache = defaultdict(dict)
+        for book_id, fmt, name in self.conn.get(
+                'SELECT book,format,name FROM data'):
+            self.format_filename_cache[book_id][fmt.upper() if fmt else ''] = name
 
     def check_if_modified(self):
         if self.last_modified() > self.last_update_check: