diff --git a/nw/gui/dialogs/configeditor.py b/nw/gui/dialogs/configeditor.py
index 77abc231..a088d090 100644
--- a/nw/gui/dialogs/configeditor.py
+++ b/nw/gui/dialogs/configeditor.py
@@ -573,7 +573,7 @@ class GuiConfigEditEditingTab(QWidget):
             "Big document limit",
             self.bigDocLimit,
             "Disables full spell checking over the size limit.",
-            theUnit="kb"
+            theUnit="kB"
         )
 
         return