diff --git a/keystone b/keystone
index aee576a7c6..9bb51da863 160000
--- a/keystone
+++ b/keystone
@@ -1 +1 @@
-Subproject commit aee576a7c69e9937079f697b228f03aedd24e970
+Subproject commit 9bb51da863affb4d7d2ff04d5991963844d1bc56