diff --git a/src/calibre/gui2/widgets.py b/src/calibre/gui2/widgets.py
index 14005f7035..2c2bd45ac2 100644
--- a/src/calibre/gui2/widgets.py
+++ b/src/calibre/gui2/widgets.py
@@ -15,7 +15,7 @@ from PyQt5.Qt import (QIcon, QFont, QLabel, QListWidget, QAction,
 from calibre.gui2 import (error_dialog, pixmap_to_data, gprefs,
         warning_dialog)
 from calibre.gui2.filename_pattern_ui import Ui_Form
-from calibre import fit_image, strftime
+from calibre import fit_image, strftime, force_unicode
 from calibre.ebooks import BOOK_EXTENSIONS
 from calibre.utils.config import prefs, XMLConfig
 from calibre.gui2.progress_indicator import ProgressIndicator as _ProgressIndicator
@@ -674,7 +674,15 @@ class HistoryLineEdit(QComboBox):  # {{{
         self.addItems(items)
         self.setEditText(ct)
         self.blockSignals(False)
-        history.set(self.store_name, items)
+        try:
+            history.set(self.store_name, items)
+        except ValueError:
+            from calibre.utils.cleantext import clean_ascii_chars
+            items = [clean_ascii_chars(force_unicode(x)) for x in items]
+            try:
+                history.set(self.store_name, items)
+            except ValueError:
+                pass
 
     def setText(self, t):
         self.setEditText(t)