diff --git a/src/plugins/resourceeditor/resourcenode.cpp b/src/plugins/resourceeditor/resourcenode.cpp
index 7cb6c82e676..1d38fd960c0 100644
--- a/src/plugins/resourceeditor/resourcenode.cpp
+++ b/src/plugins/resourceeditor/resourcenode.cpp
@@ -649,8 +649,8 @@ ResourceFolderNode *SimpleResourceFolderNode::prefixNode() const
     return m_prefixNode;
 }
 
-void SimpleResourceFolderNode::addFilesAndSubfolders(QMap<PrefixFolderLang, QList<ProjectExplorer::FolderNode*> > foldersToAdd,
-                                                     QMap<PrefixFolderLang, QList<ProjectExplorer::Node*> > nodesToAdd,
+void SimpleResourceFolderNode::addFilesAndSubfolders(const QMap<PrefixFolderLang, QList<ProjectExplorer::FolderNode*> > &foldersToAdd,
+                                                     const QMap<PrefixFolderLang, QList<ProjectExplorer::Node*> > &nodesToAdd,
                                                      const QString &prefix, const QString &lang)
 {
     setNodes(nodesToAdd.value(PrefixFolderLang(prefix, m_folderName, lang)));
diff --git a/src/plugins/resourceeditor/resourcenode.h b/src/plugins/resourceeditor/resourcenode.h
index cfbdbbf1da6..95ee5129f75 100644
--- a/src/plugins/resourceeditor/resourcenode.h
+++ b/src/plugins/resourceeditor/resourcenode.h
@@ -122,8 +122,8 @@ public:
                      const QString &prefix, const QString &lang, Utils::FileName absolutePath,
                      ResourceTopLevelNode *topLevel, ResourceFolderNode *prefixNode);
     QList<ProjectExplorer::ProjectAction> supportedActions(ProjectExplorer::Node *node) const;
-    void addFilesAndSubfolders(QMap<PrefixFolderLang, QList<ProjectExplorer::FolderNode *>> foldersToAdd,
-                               QMap<PrefixFolderLang, QList<ProjectExplorer::Node *>> nodesToAdd,
+    void addFilesAndSubfolders(const QMap<PrefixFolderLang, QList<FolderNode *> > &foldersToAdd,
+                               const QMap<PrefixFolderLang, QList<Node *> > &nodesToAdd,
                                const QString &prefix, const QString &lang);
     bool addFiles(const QStringList &filePaths, QStringList *notAdded);
     bool removeFiles(const QStringList &filePaths, QStringList *notRemoved);