diff --git a/expression/builtin_cast.go b/expression/builtin_cast.go
index cca97863d8966..2e80e885e8ac5 100644
--- a/expression/builtin_cast.go
+++ b/expression/builtin_cast.go
@@ -2149,7 +2149,7 @@ func WrapWithCastAsInt(ctx sessionctx.Context, expr Expression) Expression {
 	tp.SetFlen(expr.GetType().GetFlen())
 	tp.SetDecimal(0)
 	types.SetBinChsClnFlag(tp)
-	tp.AddFlag(expr.GetType().GetFlag() & mysql.UnsignedFlag)
+	tp.AddFlag(expr.GetType().GetFlag() & (mysql.UnsignedFlag | mysql.NotNullFlag))
 	return BuildCastFunction(ctx, expr, tp)
 }
 
@@ -2163,7 +2163,7 @@ func WrapWithCastAsReal(ctx sessionctx.Context, expr Expression) Expression {
 	tp.SetFlen(mysql.MaxRealWidth)
 	tp.SetDecimal(types.UnspecifiedLength)
 	types.SetBinChsClnFlag(tp)
-	tp.AddFlag(expr.GetType().GetFlag() & mysql.UnsignedFlag)
+	tp.AddFlag(expr.GetType().GetFlag() & (mysql.UnsignedFlag | mysql.NotNullFlag))
 	return BuildCastFunction(ctx, expr, tp)
 }
 
@@ -2204,7 +2204,7 @@ func WrapWithCastAsDecimal(ctx sessionctx.Context, expr Expression) Expression {
 		tp.SetFlen(mysql.MaxDecimalWidth)
 	}
 	types.SetBinChsClnFlag(tp)
-	tp.AddFlag(expr.GetType().GetFlag() & mysql.UnsignedFlag)
+	tp.AddFlag(expr.GetType().GetFlag() & (mysql.UnsignedFlag | mysql.NotNullFlag))
 	castExpr := BuildCastFunction(ctx, expr, tp)
 	// For const item, we can use find-grained precision and scale by the result.
 	if castExpr.ConstItem(ctx.GetSessionVars().StmtCtx) {
diff --git a/expression/expr_to_pb_test.go b/expression/expr_to_pb_test.go
index 7b7dce0771248..e43f86b6785a9 100644
--- a/expression/expr_to_pb_test.go
+++ b/expression/expr_to_pb_test.go
@@ -281,8 +281,8 @@ func TestLikeFunc2Pb(t *testing.T) {
 	pbExprs, err := ExpressionsToPBList(sc, likeFuncs, client)
 	require.NoError(t, err)
 	results := []string{
-		`{"tp":10000,"children":[{"tp":5,"val":"c3RyaW5n","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":5,"val":"cGF0dGVybg==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":10000,"val":"CAA=","children":[{"tp":5,"val":"XA==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false}],"sig":30,"field_type":{"tp":8,"flag":128,"flen":-1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}],"sig":4310,"field_type":{"tp":8,"flag":524416,"flen":1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}`,
-		`{"tp":10000,"children":[{"tp":5,"val":"c3RyaW5n","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":5,"val":"JWFiYyU=","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":10000,"val":"CAA=","children":[{"tp":5,"val":"XA==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false}],"sig":30,"field_type":{"tp":8,"flag":128,"flen":-1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}],"sig":4310,"field_type":{"tp":8,"flag":524416,"flen":1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}`,
+		`{"tp":10000,"children":[{"tp":5,"val":"c3RyaW5n","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":5,"val":"cGF0dGVybg==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":10000,"val":"CAA=","children":[{"tp":5,"val":"XA==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false}],"sig":30,"field_type":{"tp":8,"flag":129,"flen":-1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}],"sig":4310,"field_type":{"tp":8,"flag":524416,"flen":1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}`,
+		`{"tp":10000,"children":[{"tp":5,"val":"c3RyaW5n","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":5,"val":"JWFiYyU=","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false},{"tp":10000,"val":"CAA=","children":[{"tp":5,"val":"XA==","sig":0,"field_type":{"tp":254,"flag":1,"flen":-1,"decimal":-1,"collate":-83,"charset":"utf8"},"has_distinct":false}],"sig":30,"field_type":{"tp":8,"flag":129,"flen":-1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}],"sig":4310,"field_type":{"tp":8,"flag":524416,"flen":1,"decimal":0,"collate":-83,"charset":"binary"},"has_distinct":false}`,
 	}
 	for i, pbExpr := range pbExprs {
 		js, err := json.Marshal(pbExpr)
diff --git a/expression/typeinfer_test.go b/expression/typeinfer_test.go
index d72f7f77547d6..22649133a6edf 100644
--- a/expression/typeinfer_test.go
+++ b/expression/typeinfer_test.go
@@ -76,7 +76,8 @@ func TestInferType(t *testing.T) {
 		c_set set('a', 'b', 'c'),
 		c_enum enum('a', 'b', 'c'),
 		c_json JSON,
-		c_year year
+		c_year year,
+		c_int_not_null int not null
 	)`
 	testKit.MustExec(sql)
 	testKit.MustExec(`set tidb_enable_noop_functions=1;`)
@@ -215,6 +216,9 @@ func (s *InferTypeSuite) createTestCase4Cast() []typeInferTestCase {
 		{"CAST(c_int_d AS TIME)", mysql.TypeDuration, charset.CharsetBin, mysql.BinaryFlag, 10, 0},
 		{"CAST(c_int_d AS UNSIGNED)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag | mysql.UnsignedFlag, 22, 0},         // TODO: flen should be 11.
 		{"CAST(c_int_d AS UNSIGNED INTEGER)", mysql.TypeLonglong, charset.CharsetBin, mysql.BinaryFlag | mysql.UnsignedFlag, 22, 0}, // TODO: flen should be 11.
+		// We need to test WrapCast*, however this function is only called when function argument needs to be converted.
+		{"c_int_not_null + 1.1", mysql.TypeNewDecimal, charset.CharsetBin, mysql.BinaryFlag | mysql.NotNullFlag, 12, 1},
+		{"c_int_not_null + 1.1E0", mysql.TypeDouble, charset.CharsetBin, mysql.BinaryFlag | mysql.NotNullFlag, -1, -1},
 	}
 }