diff --git a/src/build/expression/Expression_test.go b/src/build/expression/Expression_test.go
index 99f2ac2..62ce2d9 100644
--- a/src/build/expression/Expression_test.go
+++ b/src/build/expression/Expression_test.go
@@ -87,6 +87,8 @@ func TestExpressionParse(t *testing.T) {
 			src := []byte(test.Expression)
 			tokens := token.Tokenize(src)
 			expr := expression.Parse(tokens)
+			defer expr.Close()
+
 			assert.NotNil(t, expr)
 			assert.Equal(t, expr.String(), test.Result)
 		})
@@ -94,7 +96,7 @@ func TestExpressionParse(t *testing.T) {
 }
 
 func BenchmarkExpression(b *testing.B) {
-	src := []byte("(1+2-3*4)!=(5*6-7+8)\n")
+	src := []byte("(1+2-3*4)+(5*6-7+8)\n")
 	tokens := token.Tokenize(src)
 
 	for i := 0; i < b.N; i++ {