diff --git a/v2/pkg/protocols/common/expressions/expressions_test.go b/v2/pkg/protocols/common/expressions/expressions_test.go
index 7e4b154a..668b3b45 100644
--- a/v2/pkg/protocols/common/expressions/expressions_test.go
+++ b/v2/pkg/protocols/common/expressions/expressions_test.go
@@ -18,8 +18,12 @@ func TestEvaluate(t *testing.T) {
 		//{input: "{{hex_encode('{{')}}", expected: "7b7b", extra: map[string]interface{}{}},
 		//{input: `{{concat("{{", 123, "*", 123, "}}")}}`, expected: "{{123*123}}", extra: map[string]interface{}{}},
 		//{input: `{{concat("{{", "123*123", "}}")}}`, expected: "{{123*123}}", extra: map[string]interface{}{}},
+		//{input: `{{"{{" + '123*123' + "}}"}}`, expected: "{{123*123}}", extra: map[string]interface{}{}},
 		{input: `{{concat(123,'*',123)}}`, expected: "123*123", extra: map[string]interface{}{}},
 		{input: `{{1+1}}`, expected: "2", extra: map[string]interface{}{}},
+		{input: `{{"1"+"1"}}`, expected: "11", extra: map[string]interface{}{}},
+		{input: `{{"1" + '*' + "1"}}`, expected: "1*1", extra: map[string]interface{}{}},
+		{input: `{{"a" + 'b' + "c"}}`, expected: "abc", extra: map[string]interface{}{}},
 		{input: `{{10*2}}`, expected: "20", extra: map[string]interface{}{}},
 		{input: `{{10/2}}`, expected: "5", extra: map[string]interface{}{}},
 		{input: `{{10-2}}`, expected: "8", extra: map[string]interface{}{}},