diff --git a/src/plugins/cppeditor/cppeditorplugin.h b/src/plugins/cppeditor/cppeditorplugin.h
index aa2f06fad76..c1d86a61591 100644
--- a/src/plugins/cppeditor/cppeditorplugin.h
+++ b/src/plugins/cppeditor/cppeditorplugin.h
@@ -37,9 +37,7 @@ namespace TextEditor { class BaseTextEditor; }
 namespace CppEditor {
 namespace Internal {
 
-class CppEditorWidget;
 class CppCodeModelInspectorDialog;
-class CppQuickFixCollector;
 class CppQuickFixAssistProvider;
 
 class CppEditorPlugin : public ExtensionSystem::IPlugin
diff --git a/src/plugins/cppeditor/cppelementevaluator.h b/src/plugins/cppeditor/cppelementevaluator.h
index ffc6bd760a1..5af04956aee 100644
--- a/src/plugins/cppeditor/cppelementevaluator.h
+++ b/src/plugins/cppeditor/cppelementevaluator.h
@@ -46,7 +46,6 @@ namespace CppTools { class CppModelManager; }
 namespace CppEditor {
 namespace Internal {
 
-class CppEditorWidget;
 class CppElement;
 
 class CppElementEvaluator
diff --git a/src/plugins/cppeditor/cpphighlighter.h b/src/plugins/cppeditor/cpphighlighter.h
index 536ea30b6c9..2e4b870b048 100644
--- a/src/plugins/cppeditor/cpphighlighter.h
+++ b/src/plugins/cppeditor/cpphighlighter.h
@@ -35,7 +35,6 @@ namespace CppEditor {
 
 namespace Internal {
 
-class CppEditorWidget;
 
 class CppHighlighter : public TextEditor::SyntaxHighlighter
 {
diff --git a/src/plugins/cppeditor/cpptypehierarchy.h b/src/plugins/cppeditor/cpptypehierarchy.h
index 125fb58338c..355f87065d9 100644
--- a/src/plugins/cppeditor/cpptypehierarchy.h
+++ b/src/plugins/cppeditor/cpptypehierarchy.h
@@ -37,12 +37,9 @@ class QLabel;
 class QModelIndex;
 class QStackedLayout;
 class QStandardItem;
-template <class> class QVector;
 template <class> class QList;
 QT_END_NAMESPACE
 
-namespace Core { class IEditor; }
-
 namespace TextEditor { class TextEditorLinkLabel; }
 
 namespace Utils {
@@ -55,7 +52,6 @@ namespace Internal {
 
 class CppEditorWidget;
 class CppClass;
-class CppClassLabel;
 
 class CppTypeHierarchyModel : public QStandardItemModel
 {