diff --git a/src/slideshoweffect.cpp b/src/slideshoweffect.cpp
--- a/src/slideshoweffect.cpp
+++ b/src/slideshoweffect.cpp
@@ -148,7 +148,7 @@
 
     if ( !dir.exists() || !dir.isReadable() ) {
         qWarning() << "Folder does not exist or is not readable: "
-        << folder << endl;
+        << folder << Qt::endl;
         return;
     }