diff --git a/src/plugins/qmldesigner/components/edit3d/edit3dview.cpp b/src/plugins/qmldesigner/components/edit3d/edit3dview.cpp
index 39125c8f698..9dcc2d7abc8 100644
--- a/src/plugins/qmldesigner/components/edit3d/edit3dview.cpp
+++ b/src/plugins/qmldesigner/components/edit3d/edit3dview.cpp
@@ -920,19 +920,23 @@ void Edit3DView::addQuick3DImport()
 {
     DesignDocument *document = QmlDesignerPlugin::instance()->currentDesignDocument();
     if (document && !document->inFileComponentModelActive() && model()) {
-        const Imports imports = model()->possibleImports();
-        for (const auto &import : imports) {
-            if (import.url() == "QtQuick3D") {
-                if (!import.version().isEmpty() && import.majorVersion() >= 6) {
-                    // Prefer empty version number in Qt6 and beyond
-                    model()->changeImports({Import::createLibraryImport(
-                                                import.url(), {}, import.alias(),
-                                                import.importPaths())}, {});
-                } else {
-                    model()->changeImports({import}, {});
-                }
-                return;
+        Import qtQuick3DImport;
+        differenceCall(model()->possibleImports(), model()->imports(), [&](const auto &import) {
+            if (import.url() == "QtQuick3D")
+                qtQuick3DImport = import;
+        });
+        if (!qtQuick3DImport.isEmpty()) {
+            if (!qtQuick3DImport.version().isEmpty() && qtQuick3DImport.majorVersion() >= 6) {
+                // Prefer empty version number in Qt6 and beyond
+                model()->changeImports({Import::createLibraryImport(qtQuick3DImport.url(),
+                                                                    {},
+                                                                    qtQuick3DImport.alias(),
+                                                                    qtQuick3DImport.importPaths())},
+                                       {});
+            } else {
+                model()->changeImports({qtQuick3DImport}, {});
             }
+            return;
         }
     }
     Core::AsynchronousMessageBox::warning(tr("Failed to Add Import"),
diff --git a/src/plugins/qmldesigner/components/itemlibrary/itemlibraryview.cpp b/src/plugins/qmldesigner/components/itemlibrary/itemlibraryview.cpp
index 89b16fcd8e5..4dd5be177f5 100644
--- a/src/plugins/qmldesigner/components/itemlibrary/itemlibraryview.cpp
+++ b/src/plugins/qmldesigner/components/itemlibrary/itemlibraryview.cpp
@@ -62,7 +62,7 @@ void ItemLibraryView::modelAttached(Model *model)
     m_widget->setModel(model);
     updateImports();
     if (model)
-        m_widget->updatePossibleImports(model->possibleImports());
+        m_widget->updatePossibleImports(difference(model->possibleImports(), model->imports()));
     m_hasErrors = !rewriterView()->errors().isEmpty();
     m_widget->setFlowMode(QmlItemNode(rootModelNode()).isFlowView());
 }
diff --git a/src/plugins/qmldesigner/components/itemlibrary/itemlibrarywidget.cpp b/src/plugins/qmldesigner/components/itemlibrary/itemlibrarywidget.cpp
index 1fafc91ea6a..112453fb8d4 100644
--- a/src/plugins/qmldesigner/components/itemlibrary/itemlibrarywidget.cpp
+++ b/src/plugins/qmldesigner/components/itemlibrary/itemlibrarywidget.cpp
@@ -368,7 +368,7 @@ void ItemLibraryWidget::handlePriorityImportsChanged()
 {
     if (!m_itemLibraryInfo.isNull()) {
         m_addModuleModel->setPriorityImports(m_itemLibraryInfo->priorityImports());
-        m_addModuleModel->update(m_model->possibleImports());
+        m_addModuleModel->update(difference(m_model->possibleImports(), m_model->imports()));
     }
 }
 
diff --git a/src/plugins/qmldesigner/components/navigator/navigatortreemodel.cpp b/src/plugins/qmldesigner/components/navigator/navigatortreemodel.cpp
index 9dcf81a1738..9f664429039 100644
--- a/src/plugins/qmldesigner/components/navigator/navigatortreemodel.cpp
+++ b/src/plugins/qmldesigner/components/navigator/navigatortreemodel.cpp
@@ -901,7 +901,8 @@ void NavigatorTreeModel::addImport(const QString &importName)
 {
     Import import = Import::createLibraryImport(importName);
     if (!m_view->model()->hasImport(import, true, true)) {
-        const Imports possImports = m_view->model()->possibleImports();
+        const Imports possImports = difference(m_view->model()->possibleImports(),
+                                               m_view->model()->imports());
         for (const auto &possImport : possImports) {
             if (possImport.url() == import.url()) {
                 import = possImport;
diff --git a/src/plugins/qmldesigner/designercore/include/import.h b/src/plugins/qmldesigner/designercore/include/import.h
index ff9e90f162f..be7c76f492d 100644
--- a/src/plugins/qmldesigner/designercore/include/import.h
+++ b/src/plugins/qmldesigner/designercore/include/import.h
@@ -3,6 +3,8 @@
 
 #pragma once
 
+#include <utils/set_algorithm.h>
+
 #include <QString>
 #include <QStringList>
 #include <QMetaType>
@@ -26,16 +28,15 @@ public:
     bool hasVersion() const { return !m_version.isEmpty(); }
     bool hasAlias() const { return !m_alias.isEmpty(); }
 
-    QString url() const { return m_url; }
-    QString file() const { return m_file; }
-    QString version() const { return m_version; }
-    QString alias() const { return m_alias; }
-    QStringList importPaths() const { return m_importPathList; }
+    const QString &url() const { return m_url; }
+    const QString &file() const { return m_file; }
+    const QString &version() const { return m_version; }
+    const QString &alias() const { return m_alias; }
+    const QStringList &importPaths() const { return m_importPathList; }
 
     QString toString(bool skipAlias = false, bool skipVersion = false) const;
     QString toImportString() const;
 
-    bool operator==(const Import &other) const;
     bool isSameModule(const Import &other) const;
 
     int majorVersion() const;
@@ -43,6 +44,18 @@ public:
     static int majorFromVersion(const QString &version);
     static int minorFromVersion(const QString &version);
 
+    friend bool operator==(const Import &first, const Import &second)
+    {
+        return first.m_url == second.m_url && first.m_file == second.m_file
+               && (first.m_version == second.m_version || first.m_version.isEmpty()
+                   || second.m_version.isEmpty());
+    }
+
+    friend bool operator<(const Import &first, const Import &second)
+    {
+        return std::tie(first.m_url, first.m_file) < std::tie(second.m_url, second.m_file);
+    }
+
 private:
     Import(const QString &url, const QString &file, const QString &version, const QString &alias, const QStringList &importPaths);
 
@@ -58,6 +71,21 @@ QMLDESIGNERCORE_EXPORT size_t qHash(const Import &import);
 
 using Imports = QList<Import>;
 
+QMLDESIGNERCORE_EXPORT Imports difference(const Imports &first, const Imports &second);
+
+template<typename Callable>
+void differenceCall(const Imports &first, const Imports &second, Callable callable)
+{
+    Imports difference;
+    difference.reserve(first.size());
+
+    std::set_difference(first.begin(),
+                        first.end(),
+                        second.begin(),
+                        second.end(),
+                        Utils::make_iterator(callable));
+}
+
 } // namespace QmlDesigner
 
 Q_DECLARE_METATYPE(QmlDesigner::Import)
diff --git a/src/plugins/qmldesigner/designercore/include/model.h b/src/plugins/qmldesigner/designercore/include/model.h
index d36086777d8..89391dfe9ed 100644
--- a/src/plugins/qmldesigner/designercore/include/model.h
+++ b/src/plugins/qmldesigner/designercore/include/model.h
@@ -119,8 +119,8 @@ public:
     const Imports &possibleImports() const;
     const Imports &usedImports() const;
     void changeImports(const Imports &importsToBeAdded, const Imports &importsToBeRemoved);
-    void setPossibleImports(const Imports &possibleImports);
-    void setUsedImports(const Imports &usedImports);
+    void setPossibleImports(Imports possibleImports);
+    void setUsedImports(Imports usedImports);
     bool hasImport(const Import &import, bool ignoreAlias = true, bool allowHigherVersion = false) const;
     bool isImportPossible(const Import &import, bool ignoreAlias = true, bool allowHigherVersion = false) const;
     QString pathForImport(const Import &import);
diff --git a/src/plugins/qmldesigner/designercore/model/import.cpp b/src/plugins/qmldesigner/designercore/model/import.cpp
index 3a6914d3258..b9e7a7a9e24 100644
--- a/src/plugins/qmldesigner/designercore/model/import.cpp
+++ b/src/plugins/qmldesigner/designercore/model/import.cpp
@@ -62,11 +62,6 @@ QString Import::toString(bool skipAlias, bool skipVersion) const
     return result;
 }
 
-bool Import::operator==(const Import &other) const
-{
-    return url() == other.url() && file() == other.file() && (version() == other.version() || version().isEmpty() || other.version().isEmpty());
-}
-
 bool Import::isSameModule(const Import &other) const
 {
     if (isLibraryImport())
@@ -107,4 +102,17 @@ size_t qHash(const Import &import)
     return ::qHash(import.url()) ^ ::qHash(import.file()) ^ ::qHash(import.version()) ^ ::qHash(import.alias());
 }
 
+Imports difference(const Imports &first, const Imports &second)
+{
+    Imports difference;
+    difference.reserve(first.size());
+
+    std::set_difference(first.begin(),
+                        first.end(),
+                        second.begin(),
+                        second.end(),
+                        std::back_inserter(difference));
+
+    return difference;
+}
 } // namespace QmlDesigner
diff --git a/src/plugins/qmldesigner/designercore/model/model.cpp b/src/plugins/qmldesigner/designercore/model/model.cpp
index 33571cc3ce1..d410a3c87aa 100644
--- a/src/plugins/qmldesigner/designercore/model/model.cpp
+++ b/src/plugins/qmldesigner/designercore/model/model.cpp
@@ -127,6 +127,8 @@ void ModelPrivate::changeImports(const Imports &toBeAddedImportList,
         }
     }
 
+    std::sort(m_imports.begin(), m_imports.end());
+
     if (!removedImportList.isEmpty() || !addedImportList.isEmpty())
         notifyImportsChanged(addedImportList, removedImportList);
 }
@@ -1419,19 +1421,23 @@ void Model::changeImports(const Imports &importsToBeAdded, const Imports &import
     d->changeImports(importsToBeAdded, importsToBeRemoved);
 }
 
-void Model::setPossibleImports(const Imports &possibleImports)
+void Model::setPossibleImports(Imports possibleImports)
 {
+    std::sort(possibleImports.begin(), possibleImports.end());
+
     if (d->m_possibleImportList != possibleImports) {
-        d->m_possibleImportList = possibleImports;
-        d->notifyPossibleImportsChanged(possibleImports);
+        d->m_possibleImportList = std::move(possibleImports);
+        d->notifyPossibleImportsChanged(d->m_possibleImportList);
     }
 }
 
-void Model::setUsedImports(const Imports &usedImports)
+void Model::setUsedImports(Imports usedImports)
 {
+    std::sort(usedImports.begin(), usedImports.end());
+
     if (d->m_usedImportList != usedImports) {
-        d->m_usedImportList = usedImports;
-        d->notifyUsedImportsChanged(usedImports);
+        d->m_usedImportList = std::move(usedImports);
+        d->notifyUsedImportsChanged(d->m_usedImportList);
     }
 }
 
diff --git a/src/plugins/qmldesigner/designercore/model/model_p.h b/src/plugins/qmldesigner/designercore/model/model_p.h
index 95985482548..8cdaaac3ecb 100644
--- a/src/plugins/qmldesigner/designercore/model/model_p.h
+++ b/src/plugins/qmldesigner/designercore/model/model_p.h
@@ -203,8 +203,6 @@ public:
 
     // Imports:
     const Imports &imports() const { return m_imports; }
-    void addImport(const Import &import);
-    void removeImport(const Import &import);
     void changeImports(const Imports &importsToBeAdded, const Imports &importToBeRemoved);
     void notifyImportsChanged(const Imports &addedImports, const Imports &removedImports);
     void notifyPossibleImportsChanged(const Imports &possibleImports);