--- a/eric6/WebBrowser/WebBrowserWindow.py	Sun Dec 08 13:08:48 2019 +0100
+++ b/eric6/WebBrowser/WebBrowserWindow.py	Sat Dec 14 17:54:25 2019 +0100
@@ -689,6 +689,15 @@
                     "DnsPrefetchEnabled"))
         except (AttributeError, KeyError):
             pass
+        
+        try:
+            # Qt 5.13
+            settings.setAttribute(
+                QWebEngineSettings.PdfViewerEnabled,
+                Preferences.getWebBrowser(
+                    "PdfViewerEnabled"))
+        except (AttributeError, KeyError):
+            pass
     
     def __initActions(self):
         """