diff --git a/stretch/preferences.d/entrouvert-debian-backports b/stretch/preferences.d/entrouvert-debian-backports
index e6f9927..ee2c8dd 100644
--- a/stretch/preferences.d/entrouvert-debian-backports
+++ b/stretch/preferences.d/entrouvert-debian-backports
@@ -133,3 +133,14 @@ Pin-Priority: 900
 Package: prometheus*
 Pin: release a=stretch-backports
 Pin-Priority: 900
+
+#
+# libjs-pdf, *old* version
+#
+Package: libjs-pdf
+Pin: release o=Entr'ouvert,n=stretch
+Pin-Priority: 900
+
+Package: pdf.js-common
+Pin: release o=Entr'ouvert,n=stretch
+Pin-Priority: 900