diff --git a/src/calibre/gui2/convert/single.py b/src/calibre/gui2/convert/single.py
index 69832f77dc..818fcb8605 100644
--- a/src/calibre/gui2/convert/single.py
+++ b/src/calibre/gui2/convert/single.py
@@ -87,6 +87,7 @@ class Config(QDialog):
         self.groups.entered[(QModelIndex)].connect(self.show_group_help)
         rb = self.buttonBox.button(QDialogButtonBox.StandardButton.RestoreDefaults)
         rb.setText(_('Restore &defaults'))
+        rb.setIcon(QIcon(I('clear_left.png')))
         rb.clicked.connect(self.restore_defaults)
         self.groups.setMouseTracking(True)
         geom = gprefs.get('convert_single_dialog_geom', None)