diff --git a/src/plugins/analyzerbase/detailederrorview.cpp b/src/plugins/analyzerbase/detailederrorview.cpp
index 6b2eba80e09..f6a6f3fbc27 100644
--- a/src/plugins/analyzerbase/detailederrorview.cpp
+++ b/src/plugins/analyzerbase/detailederrorview.cpp
@@ -51,6 +51,9 @@ DetailedErrorDelegate::DetailedErrorDelegate(QListView *parent)
 QSize DetailedErrorDelegate::sizeHint(const QStyleOptionViewItem &opt,
                                       const QModelIndex &index) const
 {
+    if (!index.isValid())
+        return QStyledItemDelegate::sizeHint(opt, index);
+
     const QListView *view = qobject_cast<const QListView *>(parent());
     const int viewportWidth = view->viewport()->width();
     const bool isSelected = view->selectionModel()->currentIndex() == index;
diff --git a/src/plugins/valgrind/memcheckerrorview.cpp b/src/plugins/valgrind/memcheckerrorview.cpp
index 9862133ea36..33dc3eab242 100644
--- a/src/plugins/valgrind/memcheckerrorview.cpp
+++ b/src/plugins/valgrind/memcheckerrorview.cpp
@@ -154,9 +154,13 @@ static QString errorLocation(const QModelIndex &index, const Error &error,
                               link, linkAttr));
 }
 
-QWidget *MemcheckErrorDelegate::createDetailsWidget(const QFont & font, const QModelIndex &errorIndex, QWidget *parent) const
+QWidget *MemcheckErrorDelegate::createDetailsWidget(const QFont & font,
+                                                    const QModelIndex &errorIndex,
+                                                    QWidget *parent) const
 {
     QWidget *widget = new QWidget(parent);
+    QTC_ASSERT(errorIndex.isValid(), return widget);
+
     QVBoxLayout *layout = new QVBoxLayout;
     // code + white-space:pre so the padding (see below) works properly
     // don't include frameName here as it should wrap if required and pre-line is not supported