diff --git a/lib/pkp b/lib/pkp
index e82f712300..664b303e7d 160000
--- a/lib/pkp
+++ b/lib/pkp
@@ -1 +1 @@
-Subproject commit e82f7123002882abec10fc33c934e6742f474cf7
+Subproject commit 664b303e7d3220f43e784ac5d2f2b98ed0a53950