diff --git a/src/calibre/gui2/custom_column_widgets.py b/src/calibre/gui2/custom_column_widgets.py
index aaaa50aa59..b9825eb635 100644
--- a/src/calibre/gui2/custom_column_widgets.py
+++ b/src/calibre/gui2/custom_column_widgets.py
@@ -858,7 +858,7 @@ def populate_metadata_page(layout, db, book_id, bulk=False, two_column=False, pa
                 wij = w.widgets[c]
                 if label_width == 0:
                     font_metrics = wij.fontMetrics()
-                    colon_width = font_metrics.width(':')
+                    colon_width = font_metrics.horizontalAdvance(':')
                     if bulk:
                         label_width = (font_metrics.averageCharWidth() *
                                gprefs['edit_metadata_bulk_cc_label_length']) - colon_width
diff --git a/src/calibre/gui2/pyqt6_compat.py b/src/calibre/gui2/pyqt6_compat.py
index aefbf6100d..fecfb07b47 100644
--- a/src/calibre/gui2/pyqt6_compat.py
+++ b/src/calibre/gui2/pyqt6_compat.py
@@ -8,8 +8,8 @@
 
 from qt.core import (
     QAbstractItemView, QAction, QComboBox, QDialog, QDialogButtonBox, QDrag,
-    QEventLoop, QFrame, QImage, QIODevice, QLineEdit, QMenu, QMessageBox,
-    QModelIndex, QSinglePointEvent, Qt, QThread, QToolButton
+    QEventLoop, QFontMetrics, QFrame, QImage, QIODevice, QLineEdit, QMenu,
+    QMessageBox, QModelIndex, QSinglePointEvent, Qt, QThread, QToolButton, QPalette
 )
 
 from calibre_extensions import progress_indicator
@@ -53,8 +53,11 @@ QAction.menu = lambda self: progress_indicator.menu_for_action(self)
 QModelIndex.child = lambda self, row, column: self.model().index(row, column, self)
 
 
+# Restore QFontMetrics::width
+QFontMetrics.width = lambda self, text: self.horizontalAdvance(text)
+
 # Restore enum values to various classes
-for cls in (Qt, QDialog, QToolButton, QAbstractItemView, QDialogButtonBox, QFrame, QComboBox, QLineEdit, QAction, QImage, QIODevice):
+for cls in (Qt, QDialog, QToolButton, QAbstractItemView, QDialogButtonBox, QFrame, QComboBox, QLineEdit, QAction, QImage, QIODevice, QPalette):
     for var in tuple(vars(cls).values()):
         m = getattr(var, '__members__', {})
         for k, v in m.items():