diff --git a/src/Wt/WContainerWidget.C b/src/Wt/WContainerWidget.C
index 7f93ee604..edc782471 100644
--- a/src/Wt/WContainerWidget.C
+++ b/src/Wt/WContainerWidget.C
@@ -241,6 +241,9 @@ int WContainerWidget::indexOf(WWidget *widget) const
 
 WWidget *WContainerWidget::widget(int index) const
 {
+  if (index < 0 || index >= children_.size())
+    throw Wt::WException("WContainerWidget::widget: index " + std::to_string(index)
+      + " is out of range [0, " + std::to_string(children_.size()) + ")");
   return children_[index];
 }
 
diff --git a/src/Wt/WTableView.C b/src/Wt/WTableView.C
index c3e1a93fd..bd82aad57 100644
--- a/src/Wt/WTableView.C
+++ b/src/Wt/WTableView.C
@@ -1315,8 +1315,12 @@ WWidget* WTableView::headerWidget(int column, bool contentsOnly)
         result = headers_->widget(column - headerColumnsTable_->count());
     }
   } else
-    if (plainTable_ && column < plainTable_->columnCount())
-      result = plainTable_->elementAt(0, column)->widget(0);
+    if (plainTable_ && column < plainTable_->columnCount()) {
+      WTableCell *headerCell = plainTable_->elementAt(0, column);
+      if (headerCell->count() == 0)
+        return result;
+      result = headerCell->widget(0);
+    }
 
   if (result && contentsOnly)
     return result->find("contents");