diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index e60c6750b8d..c81c32d0270 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -4476,9 +4476,23 @@ ExpireTreeKnownAssignedTransactionIds(TransactionId xid, int nsubxids,
 void
 ExpireAllKnownAssignedTransactionIds(void)
 {
+	FullTransactionId latestXid;
+
 	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
 	KnownAssignedXidsRemovePreceding(InvalidTransactionId);
 
+	/* Reset latestCompletedXid to nextXid - 1 */
+	Assert(FullTransactionIdIsValid(ShmemVariableCache->nextXid));
+	latestXid = ShmemVariableCache->nextXid;
+	FullTransactionIdRetreat(&latestXid);
+	ShmemVariableCache->latestCompletedXid = latestXid;
+
+	/*
+	 * Any transactions that were in-progress were effectively aborted, so
+	 * advance xactCompletionCount.
+	 */
+	ShmemVariableCache->xactCompletionCount++;
+
 	/*
 	 * Reset lastOverflowedXid.  Currently, lastOverflowedXid has no use after
 	 * the call of this function.  But do this for unification with what
@@ -4496,8 +4510,18 @@ ExpireAllKnownAssignedTransactionIds(void)
 void
 ExpireOldKnownAssignedTransactionIds(TransactionId xid)
 {
+	TransactionId latestXid;
+
 	LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
 
+	/* As in ProcArrayEndTransaction, advance latestCompletedXid */
+	latestXid = xid;
+	TransactionIdRetreat(latestXid);
+	MaintainLatestCompletedXidRecovery(latestXid);
+
+	/* ... and xactCompletionCount */
+	ShmemVariableCache->xactCompletionCount++;
+
 	/*
 	 * Reset lastOverflowedXid if we know all transactions that have been
 	 * possibly running are being gone.  Not doing so could cause an incorrect