diff --git a/src/plugins/languageclient/languageclientoutline.cpp b/src/plugins/languageclient/languageclientoutline.cpp
index ee0c2074034..bddb300fe23 100644
--- a/src/plugins/languageclient/languageclientoutline.cpp
+++ b/src/plugins/languageclient/languageclientoutline.cpp
@@ -274,15 +274,12 @@ private:
     const DocumentUri m_uri;
 };
 
-Utils::TreeViewComboBox *LanguageClientOutlineWidgetFactory::createComboBox(Client *client,
-                                                                            Core::IEditor *editor)
+Utils::TreeViewComboBox *LanguageClientOutlineWidgetFactory::createComboBox(
+    Client *client, TextEditor::BaseTextEditor *editor)
 {
-    auto textEditor = qobject_cast<TextEditor::BaseTextEditor *>(editor);
-    QTC_ASSERT(textEditor, return nullptr);
-    if (!client || !client->supportsDocumentSymbols(textEditor->textDocument()))
-        return nullptr;
-
-    return new OutlineComboBox(client, textEditor);
+    if (client && client->supportsDocumentSymbols(editor->textDocument()))
+        return new OutlineComboBox(client, editor);
+    return nullptr;
 }
 
 OutlineComboBox::OutlineComboBox(Client *client, TextEditor::BaseTextEditor *editor)
diff --git a/src/plugins/languageclient/languageclientoutline.h b/src/plugins/languageclient/languageclientoutline.h
index 59a2fc70e72..d4ed8f89601 100644
--- a/src/plugins/languageclient/languageclientoutline.h
+++ b/src/plugins/languageclient/languageclientoutline.h
@@ -27,7 +27,10 @@
 
 #include <texteditor/ioutlinewidget.h>
 
-namespace TextEditor { class TextDocument; }
+namespace TextEditor {
+class TextDocument;
+class BaseTextEditor;
+} // namespace TextEditor
 namespace Utils { class TreeViewComboBox; }
 
 namespace LanguageClient {
@@ -39,7 +42,7 @@ class LanguageClientOutlineWidgetFactory : public TextEditor::IOutlineWidgetFact
 public:
     using IOutlineWidgetFactory::IOutlineWidgetFactory;
 
-    static Utils::TreeViewComboBox *createComboBox(Client *client, Core::IEditor *editor);
+    static Utils::TreeViewComboBox *createComboBox(Client *client, TextEditor::BaseTextEditor *editor);
     // IOutlineWidgetFactory interface
 public:
     bool supportsEditor(Core::IEditor *editor) const override;
diff --git a/src/plugins/languageclient/languageclientutils.cpp b/src/plugins/languageclient/languageclientutils.cpp
index 557f2f0f1cb..207b5623d28 100644
--- a/src/plugins/languageclient/languageclientutils.cpp
+++ b/src/plugins/languageclient/languageclientutils.cpp
@@ -288,10 +288,11 @@ void updateEditorToolBar(Core::IEditor *editor)
     }
 
     if (!extras->m_client) {
-        if (QWidget *comboBox = LanguageClientOutlineWidgetFactory::createComboBox(client, editor)) {
+        QWidget *comboBox = LanguageClientOutlineWidgetFactory::createComboBox(client, textEditor);
+        if (comboBox) {
             extras->m_client = client;
             extras->m_outlineAction = widget->insertExtraToolBarWidget(TextEditorWidget::Left,
-                                                                        comboBox);
+                                                                       comboBox);
         }
     }
 }