*** a/src/backend/storage/lmgr/predicate.c
--- b/src/backend/storage/lmgr/predicate.c
***************
*** 274,279 ****
--- 274,280 ----
  #define SkipSerialization(relation) \
  	((!IsolationIsSerializable()) \
  	|| ((MySerializableXact == InvalidSerializableXact)) \
+ 	|| (!IsMVCCSnapshot(GetActiveSnapshot())) \
  	|| ReleasePredicateLocksIfROSafe() \
  	|| SkipPredicateLocksForRelation(relation))