diff --git a/plan/new_plan_test.go b/plan/new_plan_test.go
index f312298464..79b97742c4 100644
--- a/plan/new_plan_test.go
+++ b/plan/new_plan_test.go
@@ -84,6 +84,11 @@ func (s *testPlanSuite) TestPredicatePushDown(c *C) {
 		first string
 		best  string
 	}{
+		{
+			sql:   "select count(*) from t a, t b where a.a = b.a",
+			first: "Join{DataScan(t)->DataScan(t)}->Selection->Aggr->Projection",
+			best:  "Join{DataScan(t)->DataScan(t)}->Aggr->Projection",
+		},
 		{
 			sql:   "select a from (select a from t where d = 0) k where k.a = 5",
 			first: "DataScan(t)->Selection->Projection->Selection->Projection",
diff --git a/plan/predicate_push_down.go b/plan/predicate_push_down.go
index d3cd56e4ac..74f862c68e 100644
--- a/plan/predicate_push_down.go
+++ b/plan/predicate_push_down.go
@@ -185,6 +185,7 @@ func (p *NewUnion) PredicatePushDown(predicates []expression.Expression) (ret []
 // PredicatePushDown implements LogicalPlan PredicatePushDown interface.
 func (p *Aggregation) PredicatePushDown(predicates []expression.Expression) ([]expression.Expression, LogicalPlan, error) {
 	// TODO: implement aggregation push down.
+	p.GetChildByIndex(0).(LogicalPlan).PredicatePushDown(nil)
 	return predicates, p, nil
 }