diff --git a/src/calibre/gui2/actions/edit_metadata.py b/src/calibre/gui2/actions/edit_metadata.py
index 6915d98a6e..b07be1904b 100644
--- a/src/calibre/gui2/actions/edit_metadata.py
+++ b/src/calibre/gui2/actions/edit_metadata.py
@@ -469,6 +469,13 @@ class EditMetadataAction(InterfaceAction):
 
     def apply_metadata_changes(self, id_map,
             title=_('Applying changed metadata'), msg=''):
+        '''
+        Apply the metadata changes in id_map to the database synchronously
+        id_map must be a mapping of ids to Metadata objects. Set any fields you
+        do not want updated in the Metadata object to null. An easy way to do
+        that is to create a metadata object as Metadata(_('Unknown')) and then
+        only set the fields you want changed on this object.
+        '''
         self.apply_id_map = list(id_map.iteritems())
         self.apply_current_idx = 0
         self.apply_failures = []
@@ -494,7 +501,7 @@ class EditMetadataAction(InterfaceAction):
             set_title = not mi.is_null('title')
             set_authors = not mi.is_null('authors')
             db.set_metadata(i, mi, commit=False, set_title=set_title,
-                    set_authors=set_authors)
+                    set_authors=set_authors, notify=False)
             self.applied_ids.append(i)
         except:
             import traceback
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index 6a94e725a0..3702de45c5 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -1756,7 +1756,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         return books_to_refresh
 
     def set_metadata(self, id, mi, ignore_errors=False, set_title=True,
-                     set_authors=True, commit=True, force_changes=False):
+                     set_authors=True, commit=True, force_changes=False,
+                     notify=True):
         '''
         Set metadata for the book `id` from the `Metadata` object `mi`
 
@@ -1865,7 +1866,8 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                          label=user_mi[key]['label'], commit=False)
         if commit:
             self.conn.commit()
-        self.notify('metadata', [id])
+        if notify:
+            self.notify('metadata', [id])
 
     def authors_sort_strings(self, id, index_is_id=False):
         '''