diff --git a/src/plugins/debugger/debuggercore.h b/src/plugins/debugger/debuggercore.h
index 3fd58068a1a..51d5a26a6bd 100644
--- a/src/plugins/debugger/debuggercore.h
+++ b/src/plugins/debugger/debuggercore.h
@@ -68,7 +68,6 @@ enum TestCases
 // Some convenience.
 void openTextEditor(const QString &titlePattern, const QString &contents);
 
-QWidget *mainWindow();
 void showModuleSymbols(const QString &moduleName, const QVector<Internal::Symbol> &symbols);
 void showModuleSections(const QString &moduleName, const QVector<Internal::Section> &sections);
 
diff --git a/src/plugins/debugger/debuggerengine.cpp b/src/plugins/debugger/debuggerengine.cpp
index 42c17f0c635..5af4d2b6f0a 100644
--- a/src/plugins/debugger/debuggerengine.cpp
+++ b/src/plugins/debugger/debuggerengine.cpp
@@ -1258,7 +1258,7 @@ void DebuggerEngine::notifyInferiorSpontaneousStop()
     showMessage(tr("Stopped."), StatusBar);
     setState(InferiorStopOk);
     if (boolSetting(RaiseOnInterrupt))
-        ICore::raiseWindow(Internal::mainWindow());
+        ICore::raiseWindow(DebuggerMainWindow::instance());
     EngineManager::activateEngine(this);
 }
 
@@ -1423,7 +1423,7 @@ void DebuggerEnginePrivate::updateState(bool alsoUpdateCompanion)
     m_detachAction.setEnabled(detachable);
 
     if (stopped)
-        QApplication::alert(mainWindow(), 3000);
+        QApplication::alert(ICore::mainWindow(), 3000);
 
     updateReverseActions();
 
diff --git a/src/plugins/debugger/debuggerplugin.cpp b/src/plugins/debugger/debuggerplugin.cpp
index 3c67eb8ada2..6c215e4e8f0 100644
--- a/src/plugins/debugger/debuggerplugin.cpp
+++ b/src/plugins/debugger/debuggerplugin.cpp
@@ -2318,11 +2318,6 @@ void openTextEditor(const QString &titlePattern0, const QString &contents)
     QTC_ASSERT(editor, return);
 }
 
-QWidget *mainWindow()
-{
-    return DebuggerMainWindow::instance();
-}
-
 QSharedPointer<Internal::GlobalDebuggerOptions> globalDebuggerOptions()
 {
     return dd->m_globalDebuggerOptions;
diff --git a/src/plugins/debugger/debuggertooltipmanager.cpp b/src/plugins/debugger/debuggertooltipmanager.cpp
index d89e1ef1de8..f3b33128963 100644
--- a/src/plugins/debugger/debuggertooltipmanager.cpp
+++ b/src/plugins/debugger/debuggertooltipmanager.cpp
@@ -24,16 +24,18 @@
 ****************************************************************************/
 
 #include "debuggertooltipmanager.h"
-#include "debuggerinternalconstants.h"
-#include "debuggerengine.h"
-#include "debuggerprotocol.h"
+
 #include "debuggeractions.h"
-#include "snapshothandler.h"
-#include "stackhandler.h"
 #include "debuggercore.h"
+#include "debuggerengine.h"
+#include "debuggerinternalconstants.h"
+#include "debuggermainwindow.h"
+#include "debuggerprotocol.h"
+#include "snapshothandler.h"
+#include "sourceutils.h"
+#include "stackhandler.h"
 #include "watchhandler.h"
 #include "watchwindow.h"
-#include "sourceutils.h"
 
 #include <coreplugin/icore.h>
 #include <coreplugin/coreconstants.h>
@@ -797,7 +799,7 @@ void DebuggerToolTipHolder::updateTooltip(DebuggerEngine *engine)
 
     if (state == PendingUnshown) {
         setState(PendingShown);
-        ToolTip::show(context.mousePosition, widget, Internal::mainWindow());
+        ToolTip::show(context.mousePosition, widget, DebuggerMainWindow::instance());
     }
 
     if (item && sameFrame) {
@@ -845,7 +847,7 @@ void DebuggerToolTipHolder::releaseEngine()
         // (Out of scope items, keywords, ...)
         ToolTip::show(context.mousePosition,
                       DebuggerToolTipManager::tr("No valid expression"),
-                      Internal::mainWindow());
+                      DebuggerMainWindow::instance());
         widget->deleteLater();
         return;
     }
@@ -1156,7 +1158,7 @@ static void slotTooltipOverrideRequested
 
     if (context.expression.isEmpty()) {
         ToolTip::show(point, DebuggerToolTipManager::tr("No valid expression"),
-                             Internal::mainWindow());
+                             DebuggerMainWindow::instance());
         *handled = true;
         return;
     }
@@ -1178,13 +1180,13 @@ static void slotTooltipOverrideRequested
         if (tooltip) {
             DEBUG("REUSING LOCALS TOOLTIP");
             tooltip->context.mousePosition = point;
-            ToolTip::move(point, Internal::mainWindow());
+            ToolTip::move(point, DebuggerMainWindow::instance());
         } else {
             DEBUG("CREATING LOCALS, WAITING...");
             tooltip = new DebuggerToolTipHolder(context);
             tooltip->setState(Acquired);
             m_tooltips.push_back(tooltip);
-            ToolTip::show(point, tooltip->widget, Internal::mainWindow());
+            ToolTip::show(point, tooltip->widget, DebuggerMainWindow::instance());
         }
         DEBUG("SYNC IN STATE" << tooltip->state);
         tooltip->updateTooltip(engine);
@@ -1202,7 +1204,7 @@ static void slotTooltipOverrideRequested
         if (tooltip) {
             //tooltip->destroy();
             tooltip->context.mousePosition = point;
-            ToolTip::move(point, Internal::mainWindow());
+            ToolTip::move(point, DebuggerMainWindow::instance());
             DEBUG("UPDATING DELAYED.");
             *handled = true;
         } else {
@@ -1215,7 +1217,7 @@ static void slotTooltipOverrideRequested
                 engine->updateItem(context.iname);
             } else {
                 ToolTip::show(point, DebuggerToolTipManager::tr("Expression too complex"),
-                              Internal::mainWindow());
+                              DebuggerMainWindow::instance());
                 tooltip->destroy();
             }
         }
diff --git a/src/plugins/debugger/watchhandler.cpp b/src/plugins/debugger/watchhandler.cpp
index 6bd122e9aed..62108c6d64c 100644
--- a/src/plugins/debugger/watchhandler.cpp
+++ b/src/plugins/debugger/watchhandler.cpp
@@ -31,6 +31,7 @@
 #include "debuggerdialogs.h"
 #include "debuggerengine.h"
 #include "debuggerinternalconstants.h"
+#include "debuggermainwindow.h"
 #include "debuggerprotocol.h"
 #include "debuggertooltipmanager.h"
 #include "imageviewer.h"
@@ -269,7 +270,7 @@ static void saveFormats()
 class SeparatedView : public QTabWidget
 {
 public:
-    SeparatedView() : QTabWidget(Internal::mainWindow())
+    SeparatedView() : QTabWidget(DebuggerMainWindow::instance())
     {
         setTabsClosable(true);
         connect(this, &QTabWidget::tabCloseRequested, this, &SeparatedView::closeTab);
@@ -1975,8 +1976,7 @@ void WatchHandler::cleanup()
     saveWatchers();
     m_model->reinitialize();
     emit m_model->updateFinished();
-    if (Internal::mainWindow())
-        m_model->m_separatedView->hide();
+    m_model->m_separatedView->hide();
 }
 
 static bool sortByName(const WatchItem *a, const WatchItem *b)