diff --git a/src/calibre/gui2/tweak_book/editor/text.py b/src/calibre/gui2/tweak_book/editor/text.py
index 497265644a..ac00fe244b 100644
--- a/src/calibre/gui2/tweak_book/editor/text.py
+++ b/src/calibre/gui2/tweak_book/editor/text.py
@@ -48,6 +48,7 @@ def get_smarts(syntax):
         except (ImportError, AttributeError):
             pass
 
+
 _dff = None
 
 
diff --git a/src/calibre/gui2/tweak_book/preferences.py b/src/calibre/gui2/tweak_book/preferences.py
index f8fd1b8c92..1cbc7dfe62 100644
--- a/src/calibre/gui2/tweak_book/preferences.py
+++ b/src/calibre/gui2/tweak_book/preferences.py
@@ -768,6 +768,7 @@ class Preferences(QDialog):
         tprefs.set('preferences_geom', bytearray(self.saveGeometry()))
         QDialog.reject(self)
 
+
 if __name__ == '__main__':
     from calibre.gui2 import Application
     from calibre.gui2.tweak_book.main import option_parser
diff --git a/src/calibre/gui2/tweak_book/widgets.py b/src/calibre/gui2/tweak_book/widgets.py
index 6725e7ae40..154ec49f7e 100644
--- a/src/calibre/gui2/tweak_book/widgets.py
+++ b/src/calibre/gui2/tweak_book/widgets.py
@@ -1195,6 +1195,7 @@ class PlainTextEdit(QPlainTextEdit):  # {{{
 
 # }}}
 
+
 if __name__ == '__main__':
     app = QApplication([])
     AddCover.test()