diff --git a/src/plugins/coreplugin/editormanager/documentmodel.cpp b/src/plugins/coreplugin/editormanager/documentmodel.cpp
index 10960e47934..fb6bf689493 100644
--- a/src/plugins/coreplugin/editormanager/documentmodel.cpp
+++ b/src/plugins/coreplugin/editormanager/documentmodel.cpp
@@ -367,6 +367,7 @@ DocumentModel::Entry *DocumentModelPrivate::removeEditor(IEditor *editor)
     QTC_ASSERT(d->m_editors.contains(document), return nullptr);
     d->m_editors[document].removeAll(editor);
     DocumentModel::Entry *entry = DocumentModel::entryForDocument(document);
+    QTC_ASSERT(entry, return nullptr);
     if (d->m_editors.value(document).isEmpty()) {
         d->m_editors.remove(document);
         entry->document = new IDocument;