diff --git a/lib/requestIterator.js b/lib/requestIterator.js
index 7886e592..5c1d27e0 100644
--- a/lib/requestIterator.js
+++ b/lib/requestIterator.js
@@ -1,6 +1,6 @@
 'use strict'
 
-const hyperid = require('hyperid')(true)
+const hyperid = require('hyperid')
 const inherits = require('util').inherits
 const requestBuilder = require('./httpRequestBuilder')
 const clone = require('lodash.clonedeep')
@@ -26,6 +26,7 @@ function RequestIterator (opts) {
     return new RequestIterator(opts)
   }
 
+  this.hyperid = hyperid({ urlSafe: true })
   this.resetted = false
   this.headers = {}
   this.initialContext = opts.initialContext || {}
@@ -108,7 +109,7 @@ RequestIterator.prototype.rebuildRequest = function () {
     data = this.requestBuilder(this.currentRequest, this.context)
     if (data) {
       this.currentRequest.requestBuffer = this.reqDefaults.idReplacement
-        ? Buffer.from(data.toString().replace(/\[<id>\]/g, hyperid()))
+        ? Buffer.from(data.toString().replace(/\[<id>\]/g, this.hyperid()))
         : data
     } else if (this.currentRequestIndex === 0) {
       // when first request fails to build, we can not reset pipeline, or it'll never end
diff --git a/test/requestIterator.test.js b/test/requestIterator.test.js
index 1ca6a72d..07f7a0ef 100644
--- a/test/requestIterator.test.js
+++ b/test/requestIterator.test.js
@@ -202,7 +202,11 @@ test('request iterator should not replace any [<id>] tags with generated IDs whe
 })
 
 test('request iterator should replace all [<id>] tags with generated IDs when calling move with idReplacement enabled', (t) => {
-  t.plan(4)
+  t.plan(6)
+
+  function isUrlSafe (string) {
+    return /^[A-Za-z0-9\-_]+$/.test(string)
+  }
 
   const opts = server.address()
   opts.method = 'POST'
@@ -212,15 +216,19 @@ test('request iterator should replace all [<id>] tags with generated IDs when ca
 
   const iterator = new RequestIterator(opts)
   const first = iterator.currentRequest.requestBuffer.toString().trim()
+  const firstId = first.split('\n').pop().trim()
 
   t.equal(first.includes('[<id>]'), false, 'One or more [<id>] tags were not replaced')
-  t.equal(first.slice(-1), '0', 'Generated ID should end with request number')
+  t.ok(firstId.endsWith('0'), 'Generated ID should end with request number')
+  t.ok(isUrlSafe(firstId), 'Generated ID should be URL-safe')
 
   iterator.nextRequest()
   const second = iterator.currentRequest.requestBuffer.toString().trim()
+  const secondId = second.split('\n').pop().trim()
 
   t.equal(second.includes('[<id>]'), false, 'One or more [<id>] tags were not replaced')
-  t.equal(second.slice(-1), '1', 'Generated ID should end with a unique request number')
+  t.ok(secondId.endsWith('1'), 'Generated ID should end with a unique request number')
+  t.ok(isUrlSafe(secondId), 'Generated ID should be URL-safe')
 })
 
 test('request iterator should invoke onResponse callback when set', (t) => {