diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index b94110d871d..08f9a0eb795 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -2031,8 +2031,12 @@ void ProjectExplorerPluginPrivate::savePersistentSettings()
     }
 
     QSettings *s = ICore::settings();
-    if (!SessionManager::isDefaultVirgin())
-        s->setValue(QLatin1String("ProjectExplorer/StartupSession"), SessionManager::activeSession());
+    if (SessionManager::isDefaultVirgin()) {
+        s->remove(Constants::STARTUPSESSION_KEY);
+    } else {
+        s->setValue(Constants::STARTUPSESSION_KEY, SessionManager::activeSession());
+        s->setValue(Constants::LASTSESSION_KEY, SessionManager::activeSession());
+    }
     s->remove(QLatin1String("ProjectExplorer/RecentProjects/Files"));
 
     QStringList fileNames;
@@ -2217,10 +2221,10 @@ void ProjectExplorerPluginPrivate::currentModeChanged(Id mode, Id oldMode)
 void ProjectExplorerPluginPrivate::determineSessionToRestoreAtStartup()
 {
     // Process command line arguments first:
-    if (m_instance->pluginSpec()->arguments().contains(QLatin1String("-lastsession")))
-        m_sessionToRestoreAtStartup = SessionManager::lastSession();
+    const bool lastSessionArg = m_instance->pluginSpec()->arguments().contains("-lastsession");
+    m_sessionToRestoreAtStartup = lastSessionArg ? SessionManager::startupSession() : QString();
     QStringList arguments = ExtensionSystem::PluginManager::arguments();
-    if (m_sessionToRestoreAtStartup.isNull()) {
+    if (!lastSessionArg) {
         QStringList sessions = SessionManager::sessions();
         // We have command line arguments, try to find a session in them
         // Default to no session loading
@@ -2233,11 +2237,10 @@ void ProjectExplorerPluginPrivate::determineSessionToRestoreAtStartup()
         }
     }
     // Handle settings only after command line arguments:
-    if (m_sessionToRestoreAtStartup.isNull()
-        && m_projectExplorerSettings.autorestoreLastSession)
-        m_sessionToRestoreAtStartup = SessionManager::lastSession();
+    if (m_sessionToRestoreAtStartup.isEmpty() && m_projectExplorerSettings.autorestoreLastSession)
+        m_sessionToRestoreAtStartup = SessionManager::startupSession();
 
-    if (!m_sessionToRestoreAtStartup.isNull())
+    if (!m_sessionToRestoreAtStartup.isEmpty())
         ModeManager::activateMode(Core::Constants::MODE_EDIT);
 }
 
diff --git a/src/plugins/projectexplorer/projectexplorerconstants.h b/src/plugins/projectexplorer/projectexplorerconstants.h
index cc115322829..ddac904c2db 100644
--- a/src/plugins/projectexplorer/projectexplorerconstants.h
+++ b/src/plugins/projectexplorer/projectexplorerconstants.h
@@ -221,8 +221,11 @@ const char FILEOVERLAY_SCXML[]=":/projectexplorer/images/fileoverlay_scxml.png";
 const char FILEOVERLAY_PY[]=":/projectexplorer/images/fileoverlay_py.png";
 const char FILEOVERLAY_UNKNOWN[]=":/projectexplorer/images/fileoverlay_unknown.png";
 
+// Settings
 const char ADD_FILES_DIALOG_FILTER_HISTORY_KEY[] = "ProjectExplorer.AddFilesFilterKey";
 const char PROJECT_ROOT_PATH_KEY[] = "ProjectExplorer.Project.RootPath";
+const char STARTUPSESSION_KEY[] = "ProjectExplorer/SessionToRestore";
+const char LASTSESSION_KEY[] = "ProjectExplorer/StartupSession";
 
 } // namespace Constants
 } // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/session.cpp b/src/plugins/projectexplorer/session.cpp
index 040ccc6af09..b386a459342 100644
--- a/src/plugins/projectexplorer/session.cpp
+++ b/src/plugins/projectexplorer/session.cpp
@@ -1137,7 +1137,12 @@ bool SessionManager::loadSession(const QString &session, bool initial)
 
 QString SessionManager::lastSession()
 {
-    return ICore::settings()->value(QLatin1String("ProjectExplorer/StartupSession")).toString();
+    return ICore::settings()->value(Constants::LASTSESSION_KEY).toString();
+}
+
+QString SessionManager::startupSession()
+{
+    return ICore::settings()->value(Constants::STARTUPSESSION_KEY).toString();
 }
 
 void SessionManager::reportProjectLoadingProgress()
diff --git a/src/plugins/projectexplorer/session.h b/src/plugins/projectexplorer/session.h
index 3bd0b48c54e..290946f9d72 100644
--- a/src/plugins/projectexplorer/session.h
+++ b/src/plugins/projectexplorer/session.h
@@ -61,6 +61,7 @@ public:
     // higher level session management
     static QString activeSession();
     static QString lastSession();
+    static QString startupSession();
     static QStringList sessions();
     static QDateTime sessionDateTime(const QString &session);