diff --git a/src/backend/access/heap/tuptoaster.c b/src/backend/access/heap/tuptoaster.c
index 4cffd21d18..55b6b41f8c 100644
--- a/src/backend/access/heap/tuptoaster.c
+++ b/src/backend/access/heap/tuptoaster.c
@@ -40,6 +40,7 @@
 #include "utils/expandeddatum.h"
 #include "utils/fmgroids.h"
 #include "utils/rel.h"
+#include "utils/snapmgr.h"
 #include "utils/typcache.h"
 #include "utils/tqual.h"
 
@@ -81,6 +82,7 @@ static int toast_open_indexes(Relation toastrel,
 				   int *num_indexes);
 static void toast_close_indexes(Relation *toastidxs, int num_indexes,
 					LOCKMODE lock);
+static void init_toast_snapshot(Snapshot toast_snapshot);
 
 
 /* ----------
@@ -1665,6 +1667,7 @@ toast_delete_datum(Relation rel, Datum value)
 	HeapTuple	toasttup;
 	int			num_indexes;
 	int			validIndex;
+	SnapshotData	SnapshotToast;
 
 	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
 		return;
@@ -1696,8 +1699,9 @@ toast_delete_datum(Relation rel, Datum value)
 	 * sequence or not, but since we've already locked the index we might as
 	 * well use systable_beginscan_ordered.)
 	 */
+	init_toast_snapshot(&SnapshotToast);
 	toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
-										   SnapshotToast, 1, &toastkey);
+										   &SnapshotToast, 1, &toastkey);
 	while ((toasttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
 	{
 		/*
@@ -1730,6 +1734,7 @@ toastrel_valueid_exists(Relation toastrel, Oid valueid)
 	int			num_indexes;
 	int			validIndex;
 	Relation   *toastidxs;
+	SnapshotData	SnapshotToast;
 
 	/* Fetch a valid index relation */
 	validIndex = toast_open_indexes(toastrel,
@@ -1748,9 +1753,10 @@ toastrel_valueid_exists(Relation toastrel, Oid valueid)
 	/*
 	 * Is there any such chunk?
 	 */
+	init_toast_snapshot(&SnapshotToast);
 	toastscan = systable_beginscan(toastrel,
 								   RelationGetRelid(toastidxs[validIndex]),
-								   true, SnapshotToast, 1, &toastkey);
+								   true, &SnapshotToast, 1, &toastkey);
 
 	if (systable_getnext(toastscan) != NULL)
 		result = true;
@@ -1813,6 +1819,7 @@ toast_fetch_datum(struct varlena * attr)
 	int32		chunksize;
 	int			num_indexes;
 	int			validIndex;
+	SnapshotData	SnapshotToast;
 
 	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
 		elog(ERROR, "toast_fetch_datum shouldn't be called for non-ondisk datums");
@@ -1859,8 +1866,9 @@ toast_fetch_datum(struct varlena * attr)
 	 */
 	nextidx = 0;
 
+	init_toast_snapshot(&SnapshotToast);
 	toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
-										   SnapshotToast, 1, &toastkey);
+										   &SnapshotToast, 1, &toastkey);
 	while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
 	{
 		/*
@@ -1990,6 +1998,7 @@ toast_fetch_datum_slice(struct varlena * attr, int32 sliceoffset, int32 length)
 	int32		chcpyend;
 	int			num_indexes;
 	int			validIndex;
+	SnapshotData	SnapshotToast;
 
 	if (!VARATT_IS_EXTERNAL_ONDISK(attr))
 		elog(ERROR, "toast_fetch_datum_slice shouldn't be called for non-ondisk datums");
@@ -2082,9 +2091,10 @@ toast_fetch_datum_slice(struct varlena * attr, int32 sliceoffset, int32 length)
 	 *
 	 * The index is on (valueid, chunkidx) so they will come in order
 	 */
+	init_toast_snapshot(&SnapshotToast);
 	nextidx = startchunk;
 	toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
-										 SnapshotToast, nscankeys, toastkey);
+										 &SnapshotToast, nscankeys, toastkey);
 	while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
 	{
 		/*
@@ -2289,3 +2299,22 @@ toast_close_indexes(Relation *toastidxs, int num_indexes, LOCKMODE lock)
 		index_close(toastidxs[i], lock);
 	pfree(toastidxs);
 }
+
+/* ----------
+ * init_toast_snapshot
+ *
+ *	Initialize an appropriate TOAST snapshot.  We must use an MVCC snapshot
+ *	to initialize the TOAST snapshot; since we don't know which one to use,
+ *	just use the oldest one.  This is safe: at worst, we will get a "snapshot
+ *	too old" error that might have been avoided otherwise.
+ */
+static void
+init_toast_snapshot(Snapshot toast_snapshot)
+{
+	Snapshot	snapshot = GetOldestSnapshot();
+
+	if (snapshot == NULL)
+		elog(ERROR, "no known snapshots");
+
+	InitToastSnapshot(toast_snapshot, snapshot->lsn, snapshot->whenTaken);
+}
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index e1caf01c60..4bddaed33b 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -188,6 +188,9 @@ typedef struct ActiveSnapshotElt
 /* Top of the stack of active snapshots */
 static ActiveSnapshotElt *ActiveSnapshot = NULL;
 
+/* Bottom of the stack of active snapshots */
+static ActiveSnapshotElt *OldestActiveSnapshot = NULL;
+
 /*
  * Currently registered Snapshots.  Ordered in a heap by xmin, so that we can
  * quickly find the one with lowest xmin, to advance our MyPgXat->xmin.
@@ -393,6 +396,34 @@ GetLatestSnapshot(void)
 	return SecondarySnapshot;
 }
 
+/*
+ * GetOldestSnapshot
+ *
+ *		Get the oldest known snapshot, as judged by the LSN.
+ */
+Snapshot
+GetOldestSnapshot(void)
+{
+	Snapshot	OldestRegisteredSnapshot = NULL;
+	XLogRecPtr	RegisteredLSN = InvalidXLogRecPtr;
+	XLogRecPtr	ActiveLSN = InvalidXLogRecPtr;
+
+	if (!pairingheap_is_empty(&RegisteredSnapshots))
+	{
+		OldestRegisteredSnapshot = pairingheap_container(SnapshotData, ph_node,
+									pairingheap_first(&RegisteredSnapshots));
+		RegisteredLSN = OldestRegisteredSnapshot->lsn;
+	}
+
+	if (OldestActiveSnapshot != NULL)
+		ActiveLSN = OldestActiveSnapshot->as_snap->lsn;
+
+	if (XLogRecPtrIsInvalid(RegisteredLSN) || RegisteredLSN > ActiveLSN)
+		return OldestActiveSnapshot->as_snap;
+
+	return OldestRegisteredSnapshot;
+}
+
 /*
  * GetCatalogSnapshot
  *		Get a snapshot that is sufficiently up-to-date for scan of the
@@ -674,6 +705,8 @@ PushActiveSnapshot(Snapshot snap)
 	newactive->as_snap->active_count++;
 
 	ActiveSnapshot = newactive;
+	if (OldestActiveSnapshot == NULL)
+		OldestActiveSnapshot = ActiveSnapshot;
 }
 
 /*
@@ -744,6 +777,8 @@ PopActiveSnapshot(void)
 
 	pfree(ActiveSnapshot);
 	ActiveSnapshot = newstack;
+	if (ActiveSnapshot == NULL)
+		OldestActiveSnapshot = NULL;
 
 	SnapshotResetXmin();
 }
@@ -953,6 +988,8 @@ AtSubAbort_Snapshot(int level)
 		pfree(ActiveSnapshot);
 
 		ActiveSnapshot = next;
+		if (ActiveSnapshot == NULL)
+			OldestActiveSnapshot = NULL;
 	}
 
 	SnapshotResetXmin();
@@ -1037,6 +1074,7 @@ AtEOXact_Snapshot(bool isCommit)
 	 * it'll go away with TopTransactionContext.
 	 */
 	ActiveSnapshot = NULL;
+	OldestActiveSnapshot = NULL;
 	pairingheap_reset(&RegisteredSnapshots);
 
 	CurrentSnapshot = NULL;
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index 2960455d6e..d99c847000 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -78,7 +78,6 @@
 /* Static variables representing various special snapshot semantics */
 SnapshotData SnapshotSelfData = {HeapTupleSatisfiesSelf};
 SnapshotData SnapshotAnyData = {HeapTupleSatisfiesAny};
-SnapshotData SnapshotToastData = {HeapTupleSatisfiesToast};
 
 /* local functions */
 static bool XidInMVCCSnapshot(TransactionId xid, Snapshot snapshot);
diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h
index 3d5dea7efb..fcd0c75b1c 100644
--- a/src/include/storage/bufmgr.h
+++ b/src/include/storage/bufmgr.h
@@ -279,7 +279,8 @@ TestForOldSnapshot(Snapshot snapshot, Relation relation, Page page)
 
 	if (old_snapshot_threshold >= 0
 		&& (snapshot) != NULL
-		&& (snapshot)->satisfies == HeapTupleSatisfiesMVCC
+		&& ((snapshot)->satisfies == HeapTupleSatisfiesMVCC
+			|| (snapshot)->satisfies == HeapTupleSatisfiesToast)
 		&& !XLogRecPtrIsInvalid((snapshot)->lsn)
 		&& PageGetLSN(page) > (snapshot)->lsn)
 		TestForOldSnapshot_impl(snapshot, relation);
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index e9414274af..9e3827249e 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -64,6 +64,7 @@ extern TransactionId RecentGlobalDataXmin;
 extern Snapshot GetTransactionSnapshot(void);
 extern Snapshot GetLatestSnapshot(void);
 extern void SnapshotSetCommandId(CommandId curcid);
+extern Snapshot GetOldestSnapshot(void);
 
 extern Snapshot GetCatalogSnapshot(Oid relid);
 extern Snapshot GetNonHistoricCatalogSnapshot(Oid relid);
diff --git a/src/include/utils/tqual.h b/src/include/utils/tqual.h
index 244594495d..8041e7b67f 100644
--- a/src/include/utils/tqual.h
+++ b/src/include/utils/tqual.h
@@ -16,25 +16,16 @@
 #define TQUAL_H
 
 #include "utils/snapshot.h"
+#include "access/xlogdefs.h"
 
 
 /* Static variables representing various special snapshot semantics */
 extern PGDLLIMPORT SnapshotData SnapshotSelfData;
 extern PGDLLIMPORT SnapshotData SnapshotAnyData;
-extern PGDLLIMPORT SnapshotData SnapshotToastData;
 extern PGDLLIMPORT SnapshotData CatalogSnapshotData;
 
 #define SnapshotSelf		(&SnapshotSelfData)
 #define SnapshotAny			(&SnapshotAnyData)
-#define SnapshotToast		(&SnapshotToastData)
-
-/*
- * We don't provide a static SnapshotDirty variable because it would be
- * non-reentrant.  Instead, users of that snapshot type should declare a
- * local variable of type SnapshotData, and initialize it with this macro.
- */
-#define InitDirtySnapshot(snapshotdata)  \
-	((snapshotdata).satisfies = HeapTupleSatisfiesDirty)
 
 /* This macro encodes the knowledge of which snapshots are MVCC-safe */
 #define IsMVCCSnapshot(snapshot)  \
@@ -100,4 +91,25 @@ extern bool ResolveCminCmaxDuringDecoding(struct HTAB *tuplecid_data,
 							  HeapTuple htup,
 							  Buffer buffer,
 							  CommandId *cmin, CommandId *cmax);
+
+/*
+ * We don't provide a static SnapshotDirty variable because it would be
+ * non-reentrant.  Instead, users of that snapshot type should declare a
+ * local variable of type SnapshotData, and initialize it with this macro.
+ */
+#define InitDirtySnapshot(snapshotdata)  \
+	((snapshotdata).satisfies = HeapTupleSatisfiesDirty)
+
+/*
+ * Similarly, some initialization is required for SnapshotToast.  We need
+ * to set lsn and whenTaken correctly to support snapshot_too_old.
+ */
+static inline void
+InitToastSnapshot(Snapshot snapshot, XLogRecPtr lsn, int64 whenTaken)
+{
+	snapshot->satisfies = HeapTupleSatisfiesToast;
+	snapshot->lsn = lsn;
+	snapshot->whenTaken = whenTaken;
+}
+
 #endif   /* TQUAL_H */