diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 24c2b60c62..9f3d0be748 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -4585,6 +4585,8 @@ bool
 ExecEvalPreOrderedDistinctMulti(AggState *aggstate, AggStatePerTrans pertrans)
 {
 	ExprContext *tmpcontext = aggstate->tmpcontext;
+	TupleTableSlot *save_outer;
+	TupleTableSlot *save_inner;
 
 	for (int i = 0; i < pertrans->numTransInputs; i++)
 	{
@@ -4596,6 +4598,10 @@ ExecEvalPreOrderedDistinctMulti(AggState *aggstate, AggStatePerTrans pertrans)
 	pertrans->sortslot->tts_nvalid = pertrans->numInputs;
 	ExecStoreVirtualTuple(pertrans->sortslot);
 
+	/* save the previous slots before we over write them. */
+	save_outer = tmpcontext->ecxt_outertuple;
+	save_inner = tmpcontext->ecxt_innertuple;
+
 	tmpcontext->ecxt_outertuple = pertrans->sortslot;
 	tmpcontext->ecxt_innertuple = pertrans->uniqslot;
 
@@ -4607,8 +4613,14 @@ ExecEvalPreOrderedDistinctMulti(AggState *aggstate, AggStatePerTrans pertrans)
 
 		pertrans->haslast = true;
 		ExecCopySlot(pertrans->uniqslot, pertrans->sortslot);
+
+		tmpcontext->ecxt_outertuple = save_outer;
+		tmpcontext->ecxt_innertuple = save_inner;
 		return true;
 	}
+
+	tmpcontext->ecxt_outertuple = save_outer;
+	tmpcontext->ecxt_innertuple = save_inner;
 	return false;
 }