diff --git a/src/lib/app/mainapplication.cpp b/src/lib/app/mainapplication.cpp
--- a/src/lib/app/mainapplication.cpp
+++ b/src/lib/app/mainapplication.cpp
@@ -960,6 +960,10 @@
     webSettings->setAttribute(QWebEngineSettings::DnsPrefetchEnabled, settings.value(QSL("DNSPrefetch"), true).toBool());
 #endif
 
+#if QTWEBENGINEWIDGETS_VERSION >= QT_VERSION_CHECK(5, 13, 0)
+    webSettings->setAttribute(QWebEngineSettings::PdfViewerEnabled, false);
+#endif
+
     webSettings->setDefaultTextEncoding(settings.value(QSL("DefaultEncoding"), webSettings->defaultTextEncoding()).toString());
 
     setWheelScrollLines(settings.value(QSL("wheelScrollLines"), wheelScrollLines()).toInt());