diff --git a/src/calibre/gui2/tweak_book/editor/syntax/base.py b/src/calibre/gui2/tweak_book/editor/syntax/base.py
index 0ba4881935..60c544083a 100644
--- a/src/calibre/gui2/tweak_book/editor/syntax/base.py
+++ b/src/calibre/gui2/tweak_book/editor/syntax/base.py
@@ -65,4 +65,6 @@ class SyntaxHighlighter(QSyntaxHighlighter):
         except:
             import traceback
             traceback.print_exc()
+        finally:
+            QApplication.processEvents()  # Try to keep the editor responsive to user input