diff --git a/clause/where.go b/clause/where.go
index 9ac78578ea..2c3c90f18f 100644
--- a/clause/where.go
+++ b/clause/where.go
@@ -215,7 +215,12 @@ func (not NotConditions) Build(builder Builder) {
 
 		for idx, c := range not.Exprs {
 			if idx > 0 {
-				builder.WriteString(AndWithSpace)
+				switch c.(type) {
+				case OrConditions:
+					builder.WriteString(OrWithSpace)
+				default:
+					builder.WriteString(AndWithSpace)
+				}
 			}
 
 			e, wrapInParentheses := c.(Expr)
diff --git a/clause/where_test.go b/clause/where_test.go
index 7d5aca1ffc..ad23a4ed53 100644
--- a/clause/where_test.go
+++ b/clause/where_test.go
@@ -113,6 +113,22 @@ func TestWhere(t *testing.T) {
 			"SELECT * FROM `users` WHERE NOT (`score` <= ? AND `age` <= ?)",
 			[]interface{}{100, 60},
 		},
+		{
+			[]clause.Interface{clause.Select{}, clause.From{}, clause.Where{
+				Exprs: []clause.Expression{
+					clause.Not(clause.AndConditions{
+						Exprs: []clause.Expression{
+							clause.Eq{Column: clause.PrimaryColumn, Value: "1"},
+							clause.Gt{Column: "age", Value: 18},
+						}}, clause.OrConditions{
+						Exprs: []clause.Expression{
+							clause.Lt{Column: "score", Value: 100},
+						},
+					}),
+				}}},
+			"SELECT * FROM `users` WHERE NOT ((`users`.`id` = ? AND `age` > ?) OR `score` < ?)",
+			[]interface{}{"1", 18, 100},
+		},
 	}
 
 	for idx, result := range results {
diff --git a/tests/query_test.go b/tests/query_test.go
index c0259a14a3..d0ed675a98 100644
--- a/tests/query_test.go
+++ b/tests/query_test.go
@@ -559,6 +559,11 @@ func TestNot(t *testing.T) {
 	if !regexp.MustCompile("SELECT \\* FROM .*users.* WHERE NOT \\(manager IS NULL AND age >= .+\\) AND .users.\\..deleted_at. IS NULL").MatchString(result.Statement.SQL.String()) {
 		t.Fatalf("Build NOT condition, but got %v", result.Statement.SQL.String())
 	}
+
+	result = dryDB.Not(DB.Where("manager IS NULL").Or("age >= ?", 20)).Find(&User{})
+	if !regexp.MustCompile(`SELECT \* FROM .*users.* WHERE NOT \(manager IS NULL OR age >= .+\) AND .users.\..deleted_at. IS NULL`).MatchString(result.Statement.SQL.String()) {
+		t.Fatalf("Build NOT condition, but got %v", result.Statement.SQL.String())
+	}
 }
 
 func TestNotWithAllFields(t *testing.T) {