diff --git a/builtin/assertion.go b/builtin/assertion.go
new file mode 100644
index 00000000..6634207f
--- /dev/null
+++ b/builtin/assertion.go
@@ -0,0 +1,15 @@
+package builtin
+
+import "github.com/stretchr/testify/assert"
+
+var Assertions = map[string]func(t assert.TestingT, expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool{
+	"equals":            assert.EqualValues,
+	"equal":             assert.EqualValues, // alias for equals
+	"greater_than":      assert.Greater,
+	"less_than":         assert.Less,
+	"greater_or_equals": assert.GreaterOrEqual,
+	"less_or_equals":    assert.LessOrEqual,
+	"not_equal":         assert.NotEqual,
+	"contains":          assert.Contains,
+	"regex_match":       assert.Regexp,
+}
diff --git a/builtin/function.go b/builtin/function.go
index 8ea6792d..e240fa16 100644
--- a/builtin/function.go
+++ b/builtin/function.go
@@ -2,7 +2,7 @@ package builtin
 
 import "time"
 
-var FunctionsMap = map[string]interface{}{
+var Functions = map[string]interface{}{
 	"sleep": Sleep,
 }
 
diff --git a/parser.go b/parser.go
index 7b8ee46d..b9023a9c 100644
--- a/parser.go
+++ b/parser.go
@@ -170,7 +170,7 @@ func mergeVariables(variables, overriddenVariables map[string]interface{}) map[s
 }
 
 func callFunction(funcName string, params []interface{}) (interface{}, error) {
-	function, ok := builtin.FunctionsMap[funcName]
+	function, ok := builtin.Functions[funcName]
 	if !ok {
 		// function not found
 		return nil, fmt.Errorf("function %s is not found", funcName)
diff --git a/response.go b/response.go
index 816246ad..60c01b6b 100644
--- a/response.go
+++ b/response.go
@@ -8,20 +8,9 @@ import (
 
 	"github.com/imroc/req"
 	"github.com/jmespath/go-jmespath"
-	"github.com/stretchr/testify/assert"
-)
 
-var assertFunctionsMap = map[string]func(t assert.TestingT, expected interface{}, actual interface{}, msgAndArgs ...interface{}) bool{
-	"equals":            assert.EqualValues,
-	"equal":             assert.EqualValues, // alias for equals
-	"greater_than":      assert.Greater,
-	"less_than":         assert.Less,
-	"greater_or_equals": assert.GreaterOrEqual,
-	"less_or_equals":    assert.LessOrEqual,
-	"not_equal":         assert.NotEqual,
-	"contains":          assert.Contains,
-	"regex_match":       assert.Regexp,
-}
+	"github.com/httprunner/httpboomer/builtin"
+)
 
 func NewResponseObject(t *testing.T, resp *req.Resp) *ResponseObject {
 	// prepare response headers
@@ -111,7 +100,7 @@ func (v *ResponseObject) Validate(validators []TValidator, variablesMapping map[
 
 		// get assert method
 		assertMethod := validator.Assert
-		assertFunc := assertFunctionsMap[assertMethod]
+		assertFunc := builtin.Assertions[assertMethod]
 
 		// parse expected value
 		expectValue := parseData(validator.Expect, variablesMapping)