diff --git a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
index 8ec0c29246f..a0bfa812116 100644
--- a/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
+++ b/src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.cpp
@@ -118,6 +118,9 @@ QmlProjectRunConfiguration::QmlProjectRunConfiguration(Target *target, Id id)
         if (m_multiLanguageAspect && m_multiLanguageAspect->value() && !m_multiLanguageAspect->databaseFilePath().isEmpty()) {
             env.set("QT_MULTILANGUAGE_DATABASE", m_multiLanguageAspect->databaseFilePath().toString());
             env.set("QT_MULTILANGUAGE_LANGUAGE", m_multiLanguageAspect->lastUsedLanguage());
+        } else {
+            env.unset("QT_MULTILANGUAGE_DATABASE");
+            env.unset("QT_MULTILANGUAGE_LANGUAGE");
         }
         return env;
     };