diff --git a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
index 2e7186db0d0..aa6b0e85652 100644
--- a/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
+++ b/src/plugins/qmldesigner/qmlpreviewplugin/qmlpreviewplugin.cpp
@@ -152,7 +152,7 @@ void QmlPreviewPlugin::setZoomFactor(float zoomFactor)
 
 void QmlPreviewPlugin::setLanguageLocale(const QString &locale)
 {
-    if (s_previewPlugin)
+    if (auto s_previewPlugin = getPreviewPlugin())
         s_previewPlugin->setProperty("locale", locale);
 }
 
diff --git a/src/plugins/qmlpreview/qmlpreviewruncontrol.cpp b/src/plugins/qmlpreview/qmlpreviewruncontrol.cpp
index 9f22796689e..2dd822fa4e0 100644
--- a/src/plugins/qmlpreview/qmlpreviewruncontrol.cpp
+++ b/src/plugins/qmlpreview/qmlpreviewruncontrol.cpp
@@ -151,6 +151,12 @@ LocalQmlPreviewSupport::LocalQmlPreviewSupport(ProjectExplorer::RunControl *runC
             runnable.setCommandLine(commandLine);
         }
 
+        if (runControl->project()) {
+            auto multilanguageDatabaseFilePath = runControl->project()->projectDirectory().pathAppended("/multilanguage-experimental-v1.db");
+            if (multilanguageDatabaseFilePath.exists())
+                runnable.environment.set("QT_MULTILANGUAGE_DATABASE", multilanguageDatabaseFilePath.toString());
+        }
+
         Utils::QtcProcess::addArg(&runnable.commandLineArguments,
                                   QmlDebug::qmlDebugLocalArguments(QmlDebug::QmlPreviewServices,
                                                                    serverUrl.path()));