diff --git a/parser_test.go b/parser_test.go
index b79f1c2b..dbf75af9 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -1,7 +1,6 @@
 package hrp
 
 import (
-	"os"
 	"sort"
 	"testing"
 	"time"
@@ -9,49 +8,6 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestLocatePlugin(t *testing.T) {
-	cwd, _ := os.Getwd()
-	_, err := locatePlugin(cwd)
-	if !assert.Error(t, err) {
-		t.Fail()
-	}
-
-	_, err = locatePlugin("")
-	if !assert.Error(t, err) {
-		t.Fail()
-	}
-
-	startPath := "examples/debugtalk.so"
-	_, err = locatePlugin(startPath)
-	if !assert.Nil(t, err) {
-		t.Fail()
-	}
-
-	startPath = "examples/demo.json"
-	_, err = locatePlugin(startPath)
-	if !assert.Nil(t, err) {
-		t.Fail()
-	}
-
-	startPath = "examples/"
-	_, err = locatePlugin(startPath)
-	if !assert.Nil(t, err) {
-		t.Fail()
-	}
-
-	startPath = "examples/plugin/debugtalk.go"
-	_, err = locatePlugin(startPath)
-	if !assert.Nil(t, err) {
-		t.Fail()
-	}
-
-	startPath = "/abc"
-	_, err = locatePlugin(startPath)
-	if !assert.Error(t, err) {
-		t.Fail()
-	}
-}
-
 func TestBuildURL(t *testing.T) {
 	var url string
 	url = buildURL("https://postman-echo.com", "/get")
diff --git a/plugin_test.go b/plugin_test.go
index 41e37684..b811c6e3 100644
--- a/plugin_test.go
+++ b/plugin_test.go
@@ -14,6 +14,7 @@ import (
 
 func TestMain(m *testing.M) {
 	fmt.Println("[TestMain] build go plugin")
+	// flag -race is necessary in order to be consistent with go test
 	cmd := exec.Command("go", "build", "-buildmode=plugin", `-race`, "-o=examples/debugtalk.so", "examples/plugin/debugtalk.go")
 	if err := cmd.Run(); err != nil {
 		panic(err)
@@ -21,6 +22,49 @@ func TestMain(m *testing.M) {
 	os.Exit(m.Run())
 }
 
+func TestLocatePlugin(t *testing.T) {
+	cwd, _ := os.Getwd()
+	_, err := locatePlugin(cwd)
+	if !assert.Error(t, err) {
+		t.Fail()
+	}
+
+	_, err = locatePlugin("")
+	if !assert.Error(t, err) {
+		t.Fail()
+	}
+
+	startPath := "examples/debugtalk.so"
+	_, err = locatePlugin(startPath)
+	if !assert.Nil(t, err) {
+		t.Fail()
+	}
+
+	startPath = "examples/demo.json"
+	_, err = locatePlugin(startPath)
+	if !assert.Nil(t, err) {
+		t.Fail()
+	}
+
+	startPath = "examples/"
+	_, err = locatePlugin(startPath)
+	if !assert.Nil(t, err) {
+		t.Fail()
+	}
+
+	startPath = "examples/plugin/debugtalk.go"
+	_, err = locatePlugin(startPath)
+	if !assert.Nil(t, err) {
+		t.Fail()
+	}
+
+	startPath = "/abc"
+	_, err = locatePlugin(startPath)
+	if !assert.Error(t, err) {
+		t.Fail()
+	}
+}
+
 func TestCallPluginFunction(t *testing.T) {
 	parser := newParser()
 	parser.loadPlugin("examples/debugtalk.so")
diff --git a/runner.go b/runner.go
index 644d2c5e..c59e1fec 100644
--- a/runner.go
+++ b/runner.go
@@ -477,8 +477,16 @@ func (r *caseRunner) runStepTestCase(step *TStep) (stepResult *stepData, err err
 		success:  false,
 	}
 	testcase := step.TestCase
+
+	// copy testcase to avoid data racing
+	copiedTestCase := &TestCase{}
+	if err = copier.Copy(copiedTestCase, testcase); err != nil {
+		log.Error().Err(err).Msg("copy testcase failed")
+		return nil, err
+	}
+
 	start := time.Now()
-	err = r.hrpRunner.newCaseRunner(testcase).run()
+	err = r.hrpRunner.newCaseRunner(copiedTestCase).run()
 	stepResult.elapsed = time.Since(start).Milliseconds()
 	if err != nil {
 		return stepResult, err