diff --git a/src/libs/extensionsystem/iplugin.cpp b/src/libs/extensionsystem/iplugin.cpp
index 42ddd05bf68..a7d35a0c4db 100644
--- a/src/libs/extensionsystem/iplugin.cpp
+++ b/src/libs/extensionsystem/iplugin.cpp
@@ -3,6 +3,8 @@
 
 #include "iplugin.h"
 
+#include "pluginmanager_p.h"
+
 #include <utils/algorithm.h>
 
 /*!
@@ -159,32 +161,16 @@
 */
 
 namespace ExtensionSystem {
-namespace Internal {
-
-class IPluginPrivate
-{
-public:
-    QList<TestCreator> testCreators;
-};
-
-} // Internal
 
 /*!
     \internal
 */
-IPlugin::IPlugin()
-    : d(new Internal::IPluginPrivate())
-{
-}
+IPlugin::IPlugin() = default;
 
 /*!
     \internal
 */
-IPlugin::~IPlugin()
-{
-    delete d;
-    d = nullptr;
-}
+IPlugin::~IPlugin() = default;
 
 bool IPlugin::initialize(const QStringList &arguments, QString *errorString)
 {
@@ -208,15 +194,8 @@ bool IPlugin::initialize(const QStringList &arguments, QString *errorString)
 
 void IPlugin::addTestCreator(const TestCreator &creator)
 {
-    d->testCreators.append(creator);
+    Internal::PluginManagerPrivate::addTestCreator(this, creator);
 }
 
-/*!
-    \deprecated [10.0] Use \c addTest() instead.
-*/
-QVector<QObject *> IPlugin::createTestObjects() const
-{
-    return Utils::transform(d->testCreators, &TestCreator::operator());
-}
 
 } // ExtensionSystem
diff --git a/src/libs/extensionsystem/iplugin.h b/src/libs/extensionsystem/iplugin.h
index b121611390f..46054a5a18f 100644
--- a/src/libs/extensionsystem/iplugin.h
+++ b/src/libs/extensionsystem/iplugin.h
@@ -37,9 +37,6 @@ public:
                                    const QStringList & /* arguments */) { return nullptr; }
 
 
-    // Deprecated in 10.0, use addTest()
-    virtual QVector<QObject *> createTestObjects() const;
-
     template <typename Test, typename ...Args>
     void addTest(Args && ...args) { addTestCreator([args...] { return new Test(args...); }); }
     void addTestCreator(const TestCreator &creator);
@@ -51,7 +48,7 @@ signals:
     void asynchronousShutdownFinished();
 
 private:
-    Internal::IPluginPrivate *d;
+    Internal::IPluginPrivate *d = nullptr; // For potential extension. Currently unused.
 };
 
 } // namespace ExtensionSystem
diff --git a/src/libs/extensionsystem/pluginmanager.cpp b/src/libs/extensionsystem/pluginmanager.cpp
index 3f9800a9505..a01329e4903 100644
--- a/src/libs/extensionsystem/pluginmanager.cpp
+++ b/src/libs/extensionsystem/pluginmanager.cpp
@@ -1079,6 +1079,15 @@ void PluginManagerPrivate::checkForDuplicatePlugins()
     }
 }
 
+static QHash<IPlugin *, QList<TestCreator>> g_testCreators;
+
+void PluginManagerPrivate::addTestCreator(IPlugin *plugin, const TestCreator &testCreator)
+{
+#ifdef WITH_TESTS
+    g_testCreators[plugin].append(testCreator);
+#endif
+}
+
 #ifdef WITH_TESTS
 
 using TestPlan = QMap<QObject *, QStringList>; // Object -> selected test functions
@@ -1289,7 +1298,8 @@ void PluginManagerPrivate::startTests()
         if (!plugin)
             continue; // plugin not loaded
 
-        const QVector<QObject *> testObjects = plugin->createTestObjects();
+        const QList<TestCreator> testCreators = g_testCreators[plugin];
+        const QVector<QObject *> testObjects = Utils::transform(testCreators, &TestCreator::operator());
         const QScopeGuard cleanup([&] { qDeleteAll(testObjects); });
 
         const bool hasDuplicateTestObjects = testObjects.size()
diff --git a/src/libs/extensionsystem/pluginmanager_p.h b/src/libs/extensionsystem/pluginmanager_p.h
index e39208eddb8..27efbf4c8f3 100644
--- a/src/libs/extensionsystem/pluginmanager_p.h
+++ b/src/libs/extensionsystem/pluginmanager_p.h
@@ -123,6 +123,8 @@ public:
     static PluginSpec *createSpec();
     static PluginSpecPrivate *privateSpec(PluginSpec *spec);
 
+    static void addTestCreator(IPlugin *plugin, const std::function<QObject *()> &testCreator);
+
     mutable QReadWriteLock m_lock;
 
     bool m_isInitializationDone = false;