diff --git a/src/async.js b/src/async.js
index fbc278b..5b98741 100644
--- a/src/async.js
+++ b/src/async.js
@@ -2,13 +2,15 @@ import * as schemas from 'har-schema'
 import Ajv from 'ajv'
 import HARError from './error'
 
-// validator config
-let ajv = new Ajv({
-  allErrors: true,
-  schemas: schemas
-})
+let ajv
 
 export function validate (name, data = {}, next) {
+  // validator config
+  ajv = ajv || new Ajv({
+    allErrors: true,
+    schemas: schemas
+  })
+
   let validate = ajv.getSchema(name + '.json')
 
   let valid = validate(data)
diff --git a/src/promise.js b/src/promise.js
index 9039dda..57b0679 100644
--- a/src/promise.js
+++ b/src/promise.js
@@ -2,13 +2,15 @@ import * as schemas from 'har-schema'
 import Ajv from 'ajv'
 import HARError from './error'
 
-// validator config
-let ajv = new Ajv({
-  allErrors: true,
-  schemas: schemas
-})
+let ajv
 
 export function validate (name, data = {}) {
+  // validator config
+  ajv = ajv || new Ajv({
+    allErrors: true,
+    schemas: schemas
+  })
+
   let validate = ajv.getSchema(name + '.json')
 
   return new Promise((resolve, reject) => {