diff --git a/cmd/explaintest/r/explain_easy.result b/cmd/explaintest/r/explain_easy.result
index 20c479463d958..b9bf7c9e94c2e 100644
--- a/cmd/explaintest/r/explain_easy.result
+++ b/cmd/explaintest/r/explain_easy.result
@@ -268,7 +268,7 @@ create table t(a int primary key, b int, c int, index idx(b));
 explain select t.c in (select count(*) from t s ignore index(idx), t t1 where s.a = t.a and s.a = t1.a) from t;
 id	count	task	operator info
 Projection_11	10000.00	root	9_aux_0
-└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, count(*))]
+└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, 7_col_0)]
   ├─TableReader_15	10000.00	root	data:TableScan_14
   │ └─TableScan_14	10000.00	cop	table:t, range:[-inf,+inf], keep order:false, stats:pseudo
   └─StreamAgg_20	1.00	root	funcs:count(1)
@@ -281,7 +281,7 @@ Projection_11	10000.00	root	9_aux_0
 explain select t.c in (select count(*) from t s use index(idx), t t1 where s.b = t.a and s.a = t1.a) from t;
 id	count	task	operator info
 Projection_11	10000.00	root	9_aux_0
-└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, count(*))]
+└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, 7_col_0)]
   ├─TableReader_15	10000.00	root	data:TableScan_14
   │ └─TableScan_14	10000.00	cop	table:t, range:[-inf,+inf], keep order:false, stats:pseudo
   └─StreamAgg_20	1.00	root	funcs:count(1)
@@ -293,7 +293,7 @@ Projection_11	10000.00	root	9_aux_0
 explain select t.c in (select count(*) from t s use index(idx), t t1 where s.b = t.a and s.c = t1.a) from t;
 id	count	task	operator info
 Projection_11	10000.00	root	9_aux_0
-└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, count(*))]
+└─Apply_13	10000.00	root	left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, 7_col_0)]
   ├─TableReader_15	10000.00	root	data:TableScan_14
   │ └─TableScan_14	10000.00	cop	table:t, range:[-inf,+inf], keep order:false, stats:pseudo
   └─StreamAgg_20	1.00	root	funcs:count(1)
diff --git a/executor/aggregate_test.go b/executor/aggregate_test.go
index 9b2d861907bcf..caf1e085a53ea 100644
--- a/executor/aggregate_test.go
+++ b/executor/aggregate_test.go
@@ -377,6 +377,11 @@ func (s *testSuite) TestAggPrune(c *C) {
 	tk.MustExec("create table t(id int primary key, b float, c float, d float)")
 	tk.MustExec("insert into t values(1, 1, 3, NULL), (2, 1, NULL, 6), (3, NULL, 1, 2), (4, NULL, NULL, 1), (5, NULL, 2, NULL), (6, 3, NULL, NULL), (7, NULL, NULL, NULL), (8, 1, 2 ,3)")
 	tk.MustQuery("select count(distinct b, c, d) from t group by id").Check(testkit.Rows("0", "0", "0", "0", "0", "0", "0", "1"))
+
+	tk.MustExec("drop table if exists t")
+	tk.MustExec("create table t(a int primary key, b varchar(10))")
+	tk.MustExec("insert into t value(1, 11),(3, NULL)")
+	tk.MustQuery("SELECT a, MIN(b), MAX(b) FROM t GROUP BY a").Check(testkit.Rows("1 11 11", "3 <nil> <nil>"))
 }
 
 func (s *testSuite) TestGroupConcatAggr(c *C) {
diff --git a/planner/core/cbo_test.go b/planner/core/cbo_test.go
index e8621d754e79f..e8d01f3353ef7 100644
--- a/planner/core/cbo_test.go
+++ b/planner/core/cbo_test.go
@@ -658,7 +658,7 @@ func (s *testAnalyzeSuite) TestCorrelatedEstimation(c *C) {
 	tk.MustQuery("explain select t.c in (select count(*) from t s , t t1 where s.a = t.a and s.a = t1.a) from t;").
 		Check(testkit.Rows(
 			"Projection_11 10.00 root 9_aux_0",
-			"└─Apply_13 10.00 root left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, count(*))]",
+			"└─Apply_13 10.00 root left outer semi join, inner:StreamAgg_20, equal:[eq(test.t.c, 7_col_0)]",
 			"  ├─TableReader_15 10.00 root data:TableScan_14",
 			"  │ └─TableScan_14 10.00 cop table:t, range:[-inf,+inf], keep order:false",
 			"  └─StreamAgg_20 1.00 root funcs:count(1)",
diff --git a/planner/core/logical_plan_test.go b/planner/core/logical_plan_test.go
index 1d268cb28181a..7efc16274c792 100644
--- a/planner/core/logical_plan_test.go
+++ b/planner/core/logical_plan_test.go
@@ -1536,11 +1536,11 @@ func (s *testPlanSuite) TestAggPrune(c *C) {
 		},
 		{
 			sql:  "select tt.a, sum(tt.b) from (select a, b from t) tt group by tt.a",
-			best: "DataScan(t)->Projection->Projection->Projection",
+			best: "DataScan(t)->Projection->Projection",
 		},
 		{
 			sql:  "select count(1) from (select count(1), a as b from t group by a) tt group by b",
-			best: "DataScan(t)->Projection->Projection->Projection->Projection",
+			best: "DataScan(t)->Projection->Projection",
 		},
 	}
 	for _, tt := range tests {
@@ -1551,7 +1551,7 @@ func (s *testPlanSuite) TestAggPrune(c *C) {
 		p, err := BuildLogicalPlan(s.ctx, stmt, s.is)
 		c.Assert(err, IsNil)
 
-		p, err = logicalOptimize(flagPredicatePushDown|flagPrunColumns|flagBuildKeyInfo|flagEliminateAgg, p.(LogicalPlan))
+		p, err = logicalOptimize(flagPredicatePushDown|flagPrunColumns|flagBuildKeyInfo|flagEliminateAgg|flagEliminateProjection, p.(LogicalPlan))
 		c.Assert(err, IsNil)
 		c.Assert(ToString(p), Equals, tt.best, comment)
 	}
diff --git a/planner/core/optimizer.go b/planner/core/optimizer.go
index 40b51540bc59a..33ff0d44e1832 100644
--- a/planner/core/optimizer.go
+++ b/planner/core/optimizer.go
@@ -33,10 +33,10 @@ var AllowCartesianProduct = true
 
 const (
 	flagPrunColumns uint64 = 1 << iota
-	flagEliminateProjection
 	flagBuildKeyInfo
 	flagDecorrelate
 	flagEliminateAgg
+	flagEliminateProjection
 	flagMaxMinEliminate
 	flagPredicatePushDown
 	flagPartitionProcessor
@@ -46,10 +46,10 @@ const (
 
 var optRuleList = []logicalOptRule{
 	&columnPruner{},
-	&projectionEliminater{},
 	&buildKeySolver{},
 	&decorrelateSolver{},
 	&aggregationEliminator{},
+	&projectionEliminater{},
 	&maxMinEliminator{},
 	&ppdSolver{},
 	&partitionProcessor{},