diff --git a/src/plugins/cppeditor/cppeditorplugin.cpp b/src/plugins/cppeditor/cppeditorplugin.cpp
index 7852855763e..24d821aac20 100644
--- a/src/plugins/cppeditor/cppeditorplugin.cpp
+++ b/src/plugins/cppeditor/cppeditorplugin.cpp
@@ -67,6 +67,8 @@
 #include <coreplugin/progressmanager/progressmanager.h>
 #include <coreplugin/vcsmanager.h>
 
+#include <extensionsystem/iplugin.h>
+
 #include <projectexplorer/project.h>
 #include <projectexplorer/projectnodes.h>
 #include <projectexplorer/projectexplorerconstants.h>
@@ -181,26 +183,35 @@ public:
     CppProjectUpdaterFactory m_cppProjectUpdaterFactory;
 };
 
-static CppEditorPlugin *m_instance = nullptr;
 static QHash<FilePath, FilePath> m_headerSourceMapping;
 
-CppEditorPlugin::CppEditorPlugin()
+class CppEditorPlugin final : public ExtensionSystem::IPlugin
 {
-    m_instance = this;
-}
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QtCreatorPlugin" FILE "CppEditor.json")
 
-CppEditorPlugin::~CppEditorPlugin()
-{
-    destroyCppQuickFixes();
-    delete d;
-    d = nullptr;
-    m_instance = nullptr;
-}
+public:
+    ~CppEditorPlugin() final
+    {
+        destroyCppQuickFixes();
+        delete d;
+        d = nullptr;
+    }
 
-CppEditorPlugin *CppEditorPlugin::instance()
-{
-    return m_instance;
-}
+private:
+    void initialize() final;
+    void extensionsInitialized() final;
+
+    void setupMenus();
+    void addPerSymbolActions();
+    void addActionsForSelections();
+    void addPerFileActions();
+    void addGlobalActions();
+    void registerVariables();
+    void registerTests();
+
+    CppEditorPluginPrivate *d = nullptr;
+};
 
 void CppEditorPlugin::initialize()
 {
@@ -540,7 +551,7 @@ void CppEditorPluginPrivate::inspectCppCodeModel()
     }
 }
 
-void CppEditorPlugin::clearHeaderSourceCache()
+void clearHeaderSourceCache()
 {
     m_headerSourceMapping.clear();
 }
@@ -774,3 +785,5 @@ FilePath correspondingHeaderOrSource(const FilePath &filePath, bool *wasHeader,
 }
 
 } // namespace CppEditor
+
+#include "cppeditorplugin.moc"
diff --git a/src/plugins/cppeditor/cppeditorplugin.h b/src/plugins/cppeditor/cppeditorplugin.h
index 4e12c3a322a..8dde52b15ea 100644
--- a/src/plugins/cppeditor/cppeditorplugin.h
+++ b/src/plugins/cppeditor/cppeditorplugin.h
@@ -3,38 +3,8 @@
 
 #pragma once
 
-#include <extensionsystem/iplugin.h>
-
 namespace CppEditor::Internal {
 
-class CppEditorPluginPrivate;
+void clearHeaderSourceCache();
 
-class CppEditorPlugin : public ExtensionSystem::IPlugin
-{
-    Q_OBJECT
-    Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QtCreatorPlugin" FILE "CppEditor.json")
-
-public:
-    CppEditorPlugin();
-    ~CppEditorPlugin() override;
-
-    static CppEditorPlugin *instance();
-
-    static void clearHeaderSourceCache();
-
-private:
-    void initialize() override;
-    void extensionsInitialized() override;
-
-    void setupMenus();
-    void addPerSymbolActions();
-    void addActionsForSelections();
-    void addPerFileActions();
-    void addGlobalActions();
-    void registerVariables();
-    void registerTests();
-
-    CppEditorPluginPrivate *d = nullptr;
-};
-
-} // namespace CppEditor::Internal
+} // CppEditor::Internal
diff --git a/src/plugins/cppeditor/cppfilesettingspage.cpp b/src/plugins/cppeditor/cppfilesettingspage.cpp
index 9a6ab7aec8b..d11a8114988 100644
--- a/src/plugins/cppeditor/cppfilesettingspage.cpp
+++ b/src/plugins/cppeditor/cppfilesettingspage.cpp
@@ -396,7 +396,7 @@ void CppFileSettingsWidget::apply()
     *m_settings = rc;
     m_settings->toSettings(Core::ICore::settings());
     m_settings->applySuffixesToMimeDB();
-    CppEditorPlugin::clearHeaderSourceCache();
+    clearHeaderSourceCache();
 }
 
 static inline void setComboText(QComboBox *cb, const QString &text, int defaultIndex = 0)
@@ -600,7 +600,7 @@ public:
         if (m_settings.useGlobalSettings() != m_wasGlobal
             || s.headerSearchPaths != m_initialSettings.headerSearchPaths
             || s.sourceSearchPaths != m_initialSettings.sourceSearchPaths) {
-            CppEditorPlugin::clearHeaderSourceCache();
+            clearHeaderSourceCache();
         }
     }
 
diff --git a/src/plugins/cppeditor/cppheadersource_test.cpp b/src/plugins/cppeditor/cppheadersource_test.cpp
index 7a195f60890..2b6621c74f0 100644
--- a/src/plugins/cppeditor/cppheadersource_test.cpp
+++ b/src/plugins/cppeditor/cppheadersource_test.cpp
@@ -49,10 +49,10 @@ void HeaderSourceTest::test()
     createTempFile(headerPath);
 
     bool wasHeader;
-    CppEditorPlugin::clearHeaderSourceCache();
+    clearHeaderSourceCache();
     QCOMPARE(correspondingHeaderOrSource(sourcePath, &wasHeader), headerPath);
     QVERIFY(!wasHeader);
-    CppEditorPlugin::clearHeaderSourceCache();
+    clearHeaderSourceCache();
     QCOMPARE(correspondingHeaderOrSource(headerPath, &wasHeader), sourcePath);
     QVERIFY(wasHeader);
 }