diff --git a/src/libs/qmljs/qmljsmodelmanagerinterface.cpp b/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
index 75cea106844..aa388312f4f 100644
--- a/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
+++ b/src/libs/qmljs/qmljsmodelmanagerinterface.cpp
@@ -139,14 +139,15 @@ ModelManagerInterface::~ModelManagerInterface()
 
 static QHash<QString, Dialect> defaultLanguageMapping()
 {
-    QHash<QString, Dialect> res;
-    res[QLatin1String("js")] = Dialect::JavaScript;
-    res[QLatin1String("qml")] = Dialect::Qml;
-    res[QLatin1String("qmltypes")] = Dialect::QmlTypeInfo;
-    res[QLatin1String("qmlproject")] = Dialect::QmlProject;
-    res[QLatin1String("json")] = Dialect::Json;
-    res[QLatin1String("qbs")] = Dialect::QmlQbs;
-    res[QLatin1String(qtQuickUISuffix)] = Dialect::QmlQtQuick2Ui;
+    static QHash<QString, Dialect> res{
+        {QLatin1String("js"), Dialect::JavaScript},
+        {QLatin1String("qml"), Dialect::Qml},
+        {QLatin1String("qmltypes"), Dialect::QmlTypeInfo},
+        {QLatin1String("qmlproject"), Dialect::QmlProject},
+        {QLatin1String("json"), Dialect::Json},
+        {QLatin1String("qbs"), Dialect::QmlQbs},
+        {QLatin1String(qtQuickUISuffix), Dialect::QmlQtQuick2Ui}
+    };
     return res;
 }
 
diff --git a/src/plugins/qmljstools/qmljsmodelmanager.cpp b/src/plugins/qmljstools/qmljsmodelmanager.cpp
index cc033ae05c7..a1c153438a1 100644
--- a/src/plugins/qmljstools/qmljsmodelmanager.cpp
+++ b/src/plugins/qmljstools/qmljsmodelmanager.cpp
@@ -168,7 +168,8 @@ void setupProjectInfoQmlBundles(ModelManagerInterface::ProjectInfo &projectInfo)
 
 namespace Internal {
 
-QHash<QString,Dialect> ModelManager::languageForSuffix() const
+
+QHash<QString,Dialect> ModelManager::initLanguageForSuffix() const
 {
     QHash<QString,Dialect> res = ModelManagerInterface::languageForSuffix();
 
@@ -196,6 +197,12 @@ QHash<QString,Dialect> ModelManager::languageForSuffix() const
     return res;
 }
 
+QHash<QString,Dialect> ModelManager::languageForSuffix() const
+{
+    static QHash<QString,Dialect> res = initLanguageForSuffix();
+    return res;
+}
+
 ModelManager::ModelManager(QObject *parent):
         ModelManagerInterface(parent)
 {
diff --git a/src/plugins/qmljstools/qmljsmodelmanager.h b/src/plugins/qmljstools/qmljsmodelmanager.h
index 6a0e630c1b0..c2ab6c4eacb 100644
--- a/src/plugins/qmljstools/qmljsmodelmanager.h
+++ b/src/plugins/qmljstools/qmljsmodelmanager.h
@@ -60,6 +60,7 @@ private slots:
     void updateDefaultProjectInfo();
 private:
     void loadDefaultQmlTypeDescriptions();
+    QHash<QString, QmlJS::Dialect> initLanguageForSuffix() const;
 };
 
 } // namespace Internal