diff --git a/src/plugins/languageclient/baseclient.cpp b/src/plugins/languageclient/baseclient.cpp
index d740fff19b8..47d1820d5f6 100644
--- a/src/plugins/languageclient/baseclient.cpp
+++ b/src/plugins/languageclient/baseclient.cpp
@@ -609,7 +609,7 @@ void BaseClient::handleMethod(const QString &method, MessageId id, const IConten
         if (paramsValid)
             log(params);
     } else if (method == ShowMessageRequest::methodName) {
-        const ShowMessageRequest *request = dynamic_cast<const ShowMessageRequest *>(content);
+        auto request = dynamic_cast<const ShowMessageRequest *>(content);
         auto params = request->params().value_or(ShowMessageRequestParams());
         paramsValid = params.isValid(&error);
         if (paramsValid) {
diff --git a/src/plugins/languageclient/dynamiccapabilities.h b/src/plugins/languageclient/dynamiccapabilities.h
index 6270c0699d6..9abee3eac9e 100644
--- a/src/plugins/languageclient/dynamiccapabilities.h
+++ b/src/plugins/languageclient/dynamiccapabilities.h
@@ -33,7 +33,7 @@ class DynamicCapability
 {
 public:
     DynamicCapability() = default;
-    void enable(QString id, QJsonValue options)
+    void enable(const QString &id, const QJsonValue &options)
     {
         QTC_CHECK(!m_enabled);
         m_enabled = true;
diff --git a/src/plugins/languageclient/languageclientmanager.cpp b/src/plugins/languageclient/languageclientmanager.cpp
index bae73aec0bf..ddb024f371c 100644
--- a/src/plugins/languageclient/languageclientmanager.cpp
+++ b/src/plugins/languageclient/languageclientmanager.cpp
@@ -290,7 +290,7 @@ void LanguageClientManager::editorOpened(Core::IEditor *iEditor)
     }
 }
 
-void LanguageClientManager::editorsClosed(const QList<Core::IEditor *> editors)
+void LanguageClientManager::editorsClosed(const QList<Core::IEditor *> &editors)
 {
     for (auto iEditor : editors) {
         if (auto editor = qobject_cast<TextEditor::BaseTextEditor *>(iEditor)) {
diff --git a/src/plugins/languageclient/languageclientmanager.h b/src/plugins/languageclient/languageclientmanager.h
index 2d41f117318..9eb9fb03c92 100644
--- a/src/plugins/languageclient/languageclientmanager.h
+++ b/src/plugins/languageclient/languageclientmanager.h
@@ -49,6 +49,8 @@ class LanguageClientManager : public QObject
 {
     Q_OBJECT
 public:
+    LanguageClientManager(const LanguageClientManager &other) = delete;
+    LanguageClientManager(LanguageClientManager &&other) = delete;
     ~LanguageClientManager() override;
 
     static void init();
@@ -78,11 +80,9 @@ signals:
 
 private:
     LanguageClientManager();
-    LanguageClientManager(const LanguageClientManager &other) = delete;
-    LanguageClientManager(LanguageClientManager &&other) = delete;
 
     void editorOpened(Core::IEditor *editor);
-    void editorsClosed(const QList<Core::IEditor *> editors);
+    void editorsClosed(const QList<Core::IEditor *> &editors);
     void documentContentsSaved(Core::IDocument *document);
     void documentWillSave(Core::IDocument *document);
     void findLinkAt(const Utils::FileName &filePath, const QTextCursor &cursor,
diff --git a/src/plugins/languageclient/languageclientsettings.cpp b/src/plugins/languageclient/languageclientsettings.cpp
index 0b8f966b736..7183bb9ab70 100644
--- a/src/plugins/languageclient/languageclientsettings.cpp
+++ b/src/plugins/languageclient/languageclientsettings.cpp
@@ -70,7 +70,7 @@ class LanguageClientSettingsModel : public QAbstractListModel
 {
 public:
     LanguageClientSettingsModel() = default;
-    ~LanguageClientSettingsModel();
+    ~LanguageClientSettingsModel() override;
 
     // QAbstractItemModel interface
     int rowCount(const QModelIndex &/*parent*/ = QModelIndex()) const final { return m_settings.count(); }
diff --git a/src/plugins/languageclient/languageclientsettings.h b/src/plugins/languageclient/languageclientsettings.h
index 8068856ae25..54877412a70 100644
--- a/src/plugins/languageclient/languageclientsettings.h
+++ b/src/plugins/languageclient/languageclientsettings.h
@@ -129,7 +129,7 @@ class BaseSettingsWidget : public QWidget
     Q_OBJECT
 public:
     explicit BaseSettingsWidget(const BaseSettings* settings, QWidget *parent = nullptr);
-    ~BaseSettingsWidget() = default;
+    ~BaseSettingsWidget() override = default;
 
     QString name() const;
     LanguageFilter filter() const;
@@ -149,7 +149,7 @@ class StdIOSettingsWidget : public BaseSettingsWidget
     Q_OBJECT
 public:
     explicit StdIOSettingsWidget(const StdIOSettings* settings, QWidget *parent = nullptr);
-    ~StdIOSettingsWidget() = default;
+    ~StdIOSettingsWidget() override = default;
 
     QString executable() const;
     QString arguments() const;