diff --git a/docs/configuration.asciidoc b/docs/configuration.asciidoc
index dc2664407..f2ca0f0c2 100644
--- a/docs/configuration.asciidoc
+++ b/docs/configuration.asciidoc
@@ -149,7 +149,9 @@ const client = new Client({
 
 const client = new Client({
   node: 'http://localhost:9200',
-  agent: () => new CustomAgent()
+  // the function takes as parameter the option
+  // object passed to the Connection constructor
+  agent: (opts) => new CustomAgent()
 })
 
 const client = new Client({
diff --git a/lib/Connection.d.ts b/lib/Connection.d.ts
index 00d1e676e..933a6a8eb 100644
--- a/lib/Connection.d.ts
+++ b/lib/Connection.d.ts
@@ -28,9 +28,9 @@ import * as https from 'https'
 import * as hpagent from 'hpagent'
 import { ConnectionOptions as TlsConnectionOptions } from 'tls'
 
-export declare type agentFn = () => any;
+export declare type agentFn = (opts: ConnectionOptions) => any;
 
-interface ConnectionOptions {
+export interface ConnectionOptions {
   url: URL;
   ssl?: TlsConnectionOptions;
   id?: string;
diff --git a/lib/Connection.js b/lib/Connection.js
index e1945b131..6bf38c495 100644
--- a/lib/Connection.js
+++ b/lib/Connection.js
@@ -53,7 +53,7 @@ class Connection {
     }
 
     if (typeof opts.agent === 'function') {
-      this.agent = opts.agent()
+      this.agent = opts.agent(opts)
     } else if (opts.agent === false) {
       this.agent = undefined
     } else {
diff --git a/lib/Helpers.js b/lib/Helpers.js
index ac8509764..6a3524b5f 100644
--- a/lib/Helpers.js
+++ b/lib/Helpers.js
@@ -104,13 +104,15 @@ class Helpers {
     }
 
     while (response.body.hits && response.body.hits.hits.length > 0) {
+      // scroll id is always present in the response, but it might
+      // change over time based on the number of shards
       scroll_id = response.body._scroll_id
       response.clear = clear
       addDocumentsGetter(response)
 
       yield response
 
-      if (!scroll_id || stop === true) {
+      if (stop === true) {
         break
       }
 
@@ -127,6 +129,10 @@ class Helpers {
         throw new ResponseError(response)
       }
     }
+
+    if (stop === false) {
+      await clear()
+    }
   }
 
   /**
diff --git a/test/types/connection.test-d.ts b/test/types/connection.test-d.ts
index df8910da6..66e9d257b 100644
--- a/test/types/connection.test-d.ts
+++ b/test/types/connection.test-d.ts
@@ -20,22 +20,35 @@
 import { expectType } from 'tsd'
 import { URL } from 'url'
 import { Connection } from '../../'
+import { ConnectionOptions } from '../../lib/Connection'
 
-const conn = new Connection({
-  url: new URL('http://localhost:9200'),
-  ssl: { ca: 'string' },
-  id: 'id',
-  headers: {},
-  agent: { keepAlive: false },
-  status: 'alive',
-  roles: { master: true },
-  auth: { username: 'username', password: 'password' }
-})
+{
+  const conn = new Connection({
+    url: new URL('http://localhost:9200'),
+    ssl: { ca: 'string' },
+    id: 'id',
+    headers: {},
+    agent: { keepAlive: false },
+    status: 'alive',
+    roles: { master: true },
+    auth: { username: 'username', password: 'password' }
+  })
 
-expectType<Connection>(conn)
-expectType<URL>(conn.url)
-expectType<string>(conn.id)
-expectType<Record<string, any>>(conn.headers)
-expectType<number>(conn.deadCount)
-expectType<number>(conn.resurrectTimeout)
-expectType<string>(conn.status)
+  expectType<Connection>(conn)
+  expectType<URL>(conn.url)
+  expectType<string>(conn.id)
+  expectType<Record<string, any>>(conn.headers)
+  expectType<number>(conn.deadCount)
+  expectType<number>(conn.resurrectTimeout)
+  expectType<string>(conn.status)
+}
+
+{
+  const conn = new Connection({
+    url: new URL('http://localhost:9200'),
+    agent (opts) {
+      expectType<ConnectionOptions>(opts)
+      return 'the agent'
+    }
+  })
+}
diff --git a/test/unit/connection.test.js b/test/unit/connection.test.js
index 0e3e6173a..c83147c8d 100644
--- a/test/unit/connection.test.js
+++ b/test/unit/connection.test.js
@@ -152,7 +152,7 @@ test('Basic (https with ssl agent)', t => {
 })
 
 test('Custom http agent', t => {
-  t.plan(5)
+  t.plan(6)
 
   function handler (req, res) {
     t.match(req.headers, {
@@ -172,7 +172,12 @@ test('Custom http agent', t => {
     agent.custom = true
     const connection = new Connection({
       url: new URL(`http://localhost:${port}`),
-      agent: () => agent
+      agent: opts => {
+        t.match(opts, {
+          url: new URL(`http://localhost:${port}`)
+        })
+        return agent
+      }
     })
     t.true(connection.agent.custom)
     connection.request({
diff --git a/test/unit/helpers/scroll.test.js b/test/unit/helpers/scroll.test.js
index cfa26c969..ca50957ee 100644
--- a/test/unit/helpers/scroll.test.js
+++ b/test/unit/helpers/scroll.test.js
@@ -27,17 +27,26 @@ test('Scroll search', async t => {
   var count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
-      t.strictEqual(params.querystring, 'scroll=1m')
+      count += 1
+      if (params.method === 'POST') {
+        t.strictEqual(params.querystring, 'scroll=1m')
+      }
+      if (count === 4) {
+        // final automated clear
+        t.strictEqual(params.method, 'DELETE')
+      }
       return {
         body: {
-          _scroll_id: count === 3 ? undefined : 'id',
+          _scroll_id: 'id',
           count,
           hits: {
-            hits: [
-              { _source: { one: 'one' } },
-              { _source: { two: 'two' } },
-              { _source: { three: 'three' } }
-            ]
+            hits: count === 3
+              ? []
+              : [
+                { _source: { one: 'one' } },
+                { _source: { two: 'two' } },
+                { _source: { three: 'three' } }
+              ]
           }
         }
       }
@@ -56,12 +65,7 @@ test('Scroll search', async t => {
 
   for await (const result of scrollSearch) {
     t.strictEqual(result.body.count, count)
-    if (count < 3) {
-      t.strictEqual(result.body._scroll_id, 'id')
-    } else {
-      t.strictEqual(result.body._scroll_id, undefined)
-    }
-    count += 1
+    t.strictEqual(result.body._scroll_id, 'id')
   }
 })
 
@@ -115,21 +119,27 @@ test('Scroll search (retry)', async t => {
   var count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
+      count += 1
       if (count === 1) {
-        count += 1
         return { body: {}, statusCode: 429 }
       }
+      if (count === 5) {
+        // final automated clear
+        t.strictEqual(params.method, 'DELETE')
+      }
       return {
         statusCode: 200,
         body: {
-          _scroll_id: count === 4 ? undefined : 'id',
+          _scroll_id: 'id',
           count,
           hits: {
-            hits: [
-              { _source: { one: 'one' } },
-              { _source: { two: 'two' } },
-              { _source: { three: 'three' } }
-            ]
+            hits: count === 4
+              ? []
+              : [
+                { _source: { one: 'one' } },
+                { _source: { two: 'two' } },
+                { _source: { three: 'three' } }
+              ]
           }
         }
       }
@@ -151,12 +161,7 @@ test('Scroll search (retry)', async t => {
   for await (const result of scrollSearch) {
     t.strictEqual(result.body.count, count)
     t.notStrictEqual(result.body.count, 1)
-    if (count < 4) {
-      t.strictEqual(result.body._scroll_id, 'id')
-    } else {
-      t.strictEqual(result.body._scroll_id, undefined)
-    }
-    count += 1
+    t.strictEqual(result.body._scroll_id, 'id')
   }
 })
 
@@ -198,20 +203,20 @@ test('Scroll search (retry throws and maxRetries)', async t => {
 
 test('Scroll search (retry throws later)', async t => {
   const maxRetries = 5
-  const expectedAttempts = maxRetries + 1
+  const expectedAttempts = maxRetries + 2
   var count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
-    // filter_path should not be added if is not already present
+      count += 1
+      // filter_path should not be added if is not already present
       t.strictEqual(params.querystring, 'scroll=1m')
       if (count > 1) {
-        count += 1
         return { body: {}, statusCode: 429 }
       }
       return {
         statusCode: 200,
         body: {
-          _scroll_id: count === 4 ? undefined : 'id',
+          _scroll_id: 'id',
           count,
           hits: {
             hits: [
@@ -227,7 +232,8 @@ test('Scroll search (retry throws later)', async t => {
 
   const client = new Client({
     node: 'http://localhost:9200',
-    Connection: MockConnection
+    Connection: MockConnection,
+    maxRetries
   })
 
   const scrollSearch = client.helpers.scrollSearch({
@@ -240,7 +246,6 @@ test('Scroll search (retry throws later)', async t => {
   try {
     for await (const result of scrollSearch) { // eslint-disable-line
       t.strictEqual(result.body.count, count)
-      count += 1
     }
   } catch (err) {
     t.true(err instanceof errors.ResponseError)
@@ -256,19 +261,23 @@ test('Scroll search documents', async t => {
       if (count === 0) {
         t.strictEqual(params.querystring, 'filter_path=hits.hits._source%2C_scroll_id&scroll=1m')
       } else {
-        t.strictEqual(params.querystring, 'scroll=1m')
-        t.strictEqual(params.body, '{"scroll_id":"id"}')
+        if (params.method !== 'DELETE') {
+          t.strictEqual(params.querystring, 'scroll=1m')
+          t.strictEqual(params.body, '{"scroll_id":"id"}')
+        }
       }
       return {
         body: {
-          _scroll_id: count === 3 ? undefined : 'id',
+          _scroll_id: 'id',
           count,
           hits: {
-            hits: [
-              { _source: { val: 1 * count } },
-              { _source: { val: 2 * count } },
-              { _source: { val: 3 * count } }
-            ]
+            hits: count === 3
+              ? []
+              : [
+                { _source: { val: 1 * count } },
+                { _source: { val: 2 * count } },
+                { _source: { val: 3 * count } }
+              ]
           }
         }
       }
@@ -339,15 +348,19 @@ test('Fix querystring for scroll search', async t => {
       if (count === 0) {
         t.strictEqual(params.querystring, 'size=1&scroll=1m')
       } else {
-        t.strictEqual(params.querystring, 'scroll=1m')
+        if (params.method !== 'DELETE') {
+          t.strictEqual(params.querystring, 'scroll=1m')
+        }
       }
       return {
         body: {
-          _scroll_id: count === 3 ? undefined : 'id',
+          _scroll_id: 'id',
           hits: {
-            hits: [
-              { _source: { val: count } }
-            ]
+            hits: count === 3
+              ? []
+              : [
+                { _source: { val: count } }
+              ]
           }
         }
       }