diff --git a/src/plugins/projectexplorer/session.cpp b/src/plugins/projectexplorer/session.cpp
index 642dbdd8974..6c3d372c47e 100644
--- a/src/plugins/projectexplorer/session.cpp
+++ b/src/plugins/projectexplorer/session.cpp
@@ -1024,7 +1024,7 @@ QStringList SessionManager::sessions() const
     return m_sessions;
 }
 
-QString SessionManager::sessionNameToFileName(const QString &session)
+QString SessionManager::sessionNameToFileName(const QString &session) const
 {
     return m_core->userResourcePath() + '/' + session + ".qws";
 }
diff --git a/src/plugins/projectexplorer/session.h b/src/plugins/projectexplorer/session.h
index 69992fba11e..14b762b2645 100644
--- a/src/plugins/projectexplorer/session.h
+++ b/src/plugins/projectexplorer/session.h
@@ -179,7 +179,7 @@ private slots:
 private:
     bool loadImpl(const QString &fileName);
     bool createImpl(const QString &fileName);
-    QString sessionNameToFileName(const QString &session);
+    QString sessionNameToFileName(const QString &session) const;
     bool projectContainsFile(Project *p, const QString &fileName) const;
 
     bool recursiveDependencyCheck(const QString &newDep, const QString &checkDep) const;