diff --git a/src/calibre/gui2/tweak_book/boss.py b/src/calibre/gui2/tweak_book/boss.py
index ded63cb952..920d9c3376 100644
--- a/src/calibre/gui2/tweak_book/boss.py
+++ b/src/calibre/gui2/tweak_book/boss.py
@@ -12,7 +12,7 @@ from urlparse import urlparse
 
 from PyQt5.Qt import (
     QObject, QApplication, QDialog, QGridLayout, QLabel, QSize, Qt,
-    QDialogButtonBox, QIcon, QTimer, QPixmap, QInputDialog, QUrl)
+    QDialogButtonBox, QIcon, QPixmap, QInputDialog, QUrl)
 
 from calibre import prints, isbytestring
 from calibre.ptempfile import PersistentTemporaryDirectory, TemporaryDirectory
@@ -76,6 +76,7 @@ class Boss(QObject):
         self.tdir = None
         self.save_manager = SaveManager(parent, notify)
         self.save_manager.report_error.connect(self.report_save_error)
+        self.save_manager.check_for_completion.connect(self.check_terminal_save)
         self.doing_terminal_save = False
         self.ignore_preview_to_editor_sync = False
         setup_cssutils_serialization()
@@ -951,8 +952,8 @@ class Boss(QObject):
     def report_save_error(self, tb):
         if self.doing_terminal_save:
             prints(tb, file=sys.stderr)
-            return
-        self.gui.action_save.setEnabled(True)
+            self.abort_terminal_save()
+        self.set_modified()
         error_dialog(self.gui, _('Could not save'),
                      _('Saving of the book failed. Click "Show Details"'
                        ' for more information. You can try to save a copy'
@@ -1370,13 +1371,15 @@ class Boss(QObject):
         self.gui.blocking_job.set_msg(_('Saving, please wait...'))
         self.gui.blocking_job.start()
         self.doing_terminal_save = True
-        QTimer.singleShot(50, self.check_terminal_save)
+
+    def abort_terminal_save(self):
+        self.doing_terminal_save = False
+        self.gui.blocking_job.stop()
 
     def check_terminal_save(self):
-        if self.save_manager.has_tasks:
-            return QTimer.singleShot(50, self.check_terminal_save)
-        self.shutdown()
-        QApplication.instance().quit()
+        if self.doing_terminal_save and not self.save_manager.has_tasks:  # terminal save could have been aborted
+            self.shutdown()
+            QApplication.instance().quit()
 
     def shutdown(self):
         self.gui.preview.stop_refresh_timer()
diff --git a/src/calibre/gui2/tweak_book/save.py b/src/calibre/gui2/tweak_book/save.py
index a20d637341..4462fcbdb2 100644
--- a/src/calibre/gui2/tweak_book/save.py
+++ b/src/calibre/gui2/tweak_book/save.py
@@ -99,6 +99,7 @@ class SaveManager(QObject):
     start_save = pyqtSignal()
     report_error = pyqtSignal(object)
     save_done = pyqtSignal()
+    check_for_completion = pyqtSignal()
 
     def __init__(self, parent, notify=None):
         QObject.__init__(self, parent)
@@ -128,14 +129,17 @@ class SaveManager(QObject):
                 self.requests.task_done()
                 self.__empty_queue()
                 break
+            error_occurred = True
             try:
                 count, tdir, container = x
-                self.process_save(count, tdir, container)
+                error_occurred = self.process_save(count, tdir, container)
             except:
                 import traceback
                 traceback.print_exc()
             finally:
                 self.requests.task_done()
+            if not error_occurred:
+                self.check_for_completion.emit()
 
     def notify_calibre(self):
         while True:
@@ -162,14 +166,17 @@ class SaveManager(QObject):
             return
         self.last_saved = count
         self.start_save.emit()
+        error_occurred = False
         try:
             self.do_save(tdir, container)
         except:
             import traceback
             self.report_error.emit(traceback.format_exc())
+            error_occurred = True
         self.save_done.emit()
         if self.notify_data:
             self.notify_requests.put(True)
+        return error_occurred
 
     def do_save(self, tdir, container):
         try: