diff --git a/src/calibre/ebooks/conversion/plugins/pdf_output.py b/src/calibre/ebooks/conversion/plugins/pdf_output.py
index db6ee84317..23fb6418a4 100644
--- a/src/calibre/ebooks/conversion/plugins/pdf_output.py
+++ b/src/calibre/ebooks/conversion/plugins/pdf_output.py
@@ -91,11 +91,12 @@ class PDFOutput(OutputFormatPlugin):
         OptionRecommendation(name='pdf_mono_font_size',
             recommended_value=16, help=_(
                 'The default font size for monospaced text')),
-        OptionRecommendation(name='uncompressed_pdf',
-            recommended_value=False, help=_(
-                'Generate an uncompressed PDF (useful for debugging)')),
-        OptionRecommendation(name='old_pdf_engine', recommended_value=False,
-            help=_('Use the old, less capable engine to generate the PDF')),
+        # OptionRecommendation(name='old_pdf_engine', recommended_value=False,
+        #     help=_('Use the old, less capable engine to generate the PDF')),
+        # OptionRecommendation(name='uncompressed_pdf',
+        #     recommended_value=False, help=_(
+        #         'Generate an uncompressed PDF, useful for debugging, '
+        #         'only works with the new PDF engine.')),
         ])
 
     def convert(self, oeb_book, output_path, input_plugin, opts, log):
@@ -189,11 +190,12 @@ class PDFOutput(OutputFormatPlugin):
                         val[i].value = family_map[k]
 
     def convert_text(self, oeb_book):
-        if self.opts.old_pdf_engine:
-            from calibre.ebooks.pdf.writer import PDFWriter
+        from calibre.utils.config import tweaks
+        if tweaks.get('new_pdf_engine', False):
+            from calibre.ebooks.pdf.render.from_html import PDFWriter
             PDFWriter
         else:
-            from calibre.ebooks.pdf.render.from_html import PDFWriter
+            from calibre.ebooks.pdf.writer import PDFWriter
         from calibre.ebooks.metadata.opf2 import OPF
 
         self.log.debug('Serializing oeb input to disk for processing...')