diff --git a/banking_breakdown/ui.py b/banking_breakdown/ui.py
index 2072793..ba0ca24 100644
--- a/banking_breakdown/ui.py
+++ b/banking_breakdown/ui.py
@@ -121,6 +121,9 @@ class MainWindow(QMainWindow):
         self._warnings.append((layout, warningIcon, label))
 
     def set_statement_data(self, df: pd.DataFrame):
+        if 'category' not in df.columns:
+            df['category'] = [' '] * len(df.index)
+
         model = PandasModel(df)
         proxyModel = QSortFilterProxyModel(self)
         proxyModel.setSourceModel(model)