diff --git a/src/filewidgets/knewfilemenu.cpp b/src/filewidgets/knewfilemenu.cpp
--- a/src/filewidgets/knewfilemenu.cpp
+++ b/src/filewidgets/knewfilemenu.cpp
@@ -902,15 +902,25 @@
     }
 
     KIO::Job *job;
+#ifdef Q_OS_WIN
     if (name.contains(QLatin1Char('/'))) {
+        // Allow creating directory tree on Windows
         // If the name contains any slashes, use mkpath so that a/b/c works.
         job = KIO::mkpath(url, baseUrl);
         KIO::FileUndoManager::self()->recordJob(KIO::FileUndoManager::Mkpath, QList<QUrl>(), url, job);
     } else {
         // If not, use mkdir so it will fail if the name of an existing folder was used
         job = KIO::mkdir(url);
         KIO::FileUndoManager::self()->recordJob(KIO::FileUndoManager::Mkdir, QList<QUrl>(), url, job);
     }
+#endif
+
+#ifdef Q_OS_UNIX
+    // Don't allow creating directory tree, since UNIX does not support / as a valid character in an identifier.
+    job = KIO::mkdir(url);
+    KIO::FileUndoManager::self()->recordJob(KIO::FileUndoManager::Mkdir, QList<QUrl>(), url, job);
+#endif
+    
     job->setProperty("newDirectoryURL", url);
     job->uiDelegate()->setAutoErrorHandlingEnabled(true);
     KJobWidgets::setWindow(job, m_parentWidget);