diff --git a/Readme.md b/Readme.md
index d4be5fdf..9ab6ab51 100644
--- a/Readme.md
+++ b/Readme.md
@@ -111,6 +111,7 @@ GitHub issues have been disabled to focus on pull requests. ([#731](https://gith
   - `wsdl_headers` (*Object*): Set HTTP headers with values to be sent on WSDL requests.
   - `wsdl_options` (*Object*): Set options for the request module on WSDL requests. If using the default request module, see [Request Config | Axios Docs](https://axios-http.com/docs/req_config).
   - `disableCache` (*boolean*): Prevents caching WSDL files and option objects.
+  - `wsdlCache` (*IWSDLCache*): Custom cache implementation. If not provided, defaults to caching WSDLs indefinitely.
   - `overridePromiseSuffix` (*string*): Override the default method name suffix of WSDL operations for Promise-based methods. If any WSDL operation name ends with `Async', you must use this option. (**Default:** `Async`)
   - `normalizeNames` (*boolean*): Replace non-identifier characters (`[^a-z$_0-9]`) with `_` in WSDL operation names. Note: Clients using WSDLs with two operations like `soap:method` and `soap-method` will be overwritten. In this case, you must use bracket notation instead (`client['soap:method']()`).
   - `namespaceArrayElements` (*boolean*): Support non-standard array semantics. JSON arrays of the form `{list: [{elem: 1}, {elem: 2}]}` will be marshalled into XML as `<list><elem>1</elem></list> <list><elem>2</elem></list>`. If `false`, it would be marshalled into `<list> <elem>1</elem> <elem>2</elem> </list>`. (**Default:** `true`)
diff --git a/src/soap.ts b/src/soap.ts
index da6245ef..69ed693f 100644
--- a/src/soap.ts
+++ b/src/soap.ts
@@ -7,7 +7,8 @@ import debugBuilder from 'debug';
 import { Client } from './client';
 import * as _security from './security';
 import { Server, ServerType } from './server';
-import { IOptions, IServerOptions, IServices } from './types';
+import { IOptions, IServerOptions, IServices, IWSDLCache } from './types';
+import { wsdlCacheSingleton } from './utils';
 import { open_wsdl, WSDL } from './wsdl';
 
 const debug = debugBuilder('node-soap:soap');
@@ -23,29 +24,22 @@ export { WSDL } from './wsdl';
 
 type WSDLCallback = (error: any, result?: WSDL) => any;
 
-function createCache() {
-  const cache: {
-    [key: string]: WSDL,
-  } = {};
-  return (key: string, load: (cb: WSDLCallback) => any, callback: WSDLCallback) => {
-    if (!cache[key]) {
-      load((err, result) => {
-        if (err) {
-          return callback(err);
-        }
-        cache[key] = result;
-        callback(null, result);
-      });
-    } else {
-      process.nextTick(() => {
-        callback(null, cache[key]);
-      });
-    }
-  };
+function getFromCache(key: string, cache: IWSDLCache, load: (cb: WSDLCallback) => any, callback: WSDLCallback) {
+  if (!cache.has(key)) {
+    load((err, result) => {
+      if (err) {
+        return callback(err);
+      }
+      cache.set(key, result);
+      callback(null, result);
+    });
+  } else {
+    process.nextTick(() => {
+      callback(null, cache.get(key));
+    });
+  }
 }
 
-const getFromCache = createCache();
-
 function _requestWSDL(url: string, options: IOptions, callback: WSDLCallback) {
   if (typeof options === 'function') {
     callback = options;
@@ -58,7 +52,13 @@ function _requestWSDL(url: string, options: IOptions, callback: WSDLCallback) {
   if (options.disableCache === true) {
     openWsdl(callback);
   } else {
-    getFromCache(url, openWsdl, callback);
+    let cache: IWSDLCache;
+    if (options.wsdlCache) {
+      cache = options.wsdlCache;
+    } else {
+      cache = wsdlCacheSingleton;
+    }
+    getFromCache(url, cache, openWsdl, callback);
   }
 }
 
diff --git a/src/types.ts b/src/types.ts
index 4e4f9819..518f8e7d 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -1,6 +1,7 @@
 
 import * as req from 'axios';
 import { ReadStream } from 'fs';
+import { WSDL } from './wsdl';
 
 export interface IHeaders {
   [k: string]: any;
@@ -117,6 +118,8 @@ export type Option = IOptions;
 export interface IOptions extends IWsdlBaseOptions {
   /** don't cache WSDL files, request them every time. */
   disableCache?: boolean;
+  /** Custom cache implementation. If not provided, defaults to caching WSDLs indefinitely. */
+  wsdlCache?: IWSDLCache;
   /** override the SOAP service's host specified in the .wsdl file. */
   endpoint?: string;
   /** set specific key instead of <pre><soap:Body></soap:Body></pre>. */
@@ -164,3 +167,9 @@ export interface IMTOMAttachments {
     headers: { [key: string]: string },
   }>;
 }
+
+export interface IWSDLCache {
+    has(key: string): boolean;
+    get(key: string): WSDL;
+    set(key: string, wsdl: WSDL): void;
+}
diff --git a/src/utils.ts b/src/utils.ts
index bfc00ea2..8025ddd1 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,6 +1,7 @@
 
 import * as crypto from 'crypto';
-import { IMTOMAttachments } from './types';
+import { IMTOMAttachments, IWSDLCache } from './types';
+import { WSDL } from './wsdl';
 
 export function passwordDigest(nonce: string, created: string, password: string): string {
   // digest = base64 ( sha1 ( nonce + created + password ) )
@@ -113,3 +114,29 @@ export function parseMTOMResp(payload: Buffer, boundary: string, callback: (err?
     })
     .catch(callback);
 }
+
+class DefaultWSDLCache implements IWSDLCache {
+  private cache: {
+    [key: string]: WSDL,
+  };
+  constructor() {
+    this.cache = {};
+  }
+
+  public has(key: string): boolean {
+    return !!this.cache[key];
+  }
+
+  public get(key: string): WSDL {
+    return this.cache[key];
+  }
+
+  public set(key: string, wsdl: WSDL) {
+    this.cache[key] = wsdl;
+  }
+
+  public clear() {
+    this.cache = {};
+  }
+}
+export const wsdlCacheSingleton = new DefaultWSDLCache();
diff --git a/test/client-options-wsdlcache-test.js b/test/client-options-wsdlcache-test.js
new file mode 100644
index 00000000..f0ac8762
--- /dev/null
+++ b/test/client-options-wsdlcache-test.js
@@ -0,0 +1,86 @@
+'use strict';
+var soap = require('..'),
+  assert = require('assert'),
+  sinon = require('sinon'),
+  utils = require('../lib/utils'),
+  wsdl  = require("../lib/wsdl");
+describe('SOAP Client - WSDL Cache', function() {
+  var sandbox = sinon.createSandbox();
+  var wsdlUri = __dirname + '/wsdl/Dummy.wsdl';
+  beforeEach(function () {
+    sandbox.spy(wsdl, 'open_wsdl');
+  });
+  afterEach(function () {
+    sandbox.restore();
+  });
+
+  it('should use default cache if not provided', function(done) {
+    // ensure cache is empty to prevent impacts to this case
+    // if other test already loaded this WSDL
+    utils.wsdlCacheSingleton.clear();
+
+    // cache miss
+    soap.createClient(wsdlUri, {}, function(err, clientFirstCall) {
+      if (err) return done(err);
+      assert.strictEqual(wsdl.open_wsdl.callCount, 1);
+
+      // hits cache
+      soap.createClient(wsdlUri, {}, function(err, clientSecondCall) {
+        if (err) return done(err);
+        assert.strictEqual(wsdl.open_wsdl.callCount, 1);
+
+        // disabled cache
+        soap.createClient(wsdlUri, {disableCache: true}, function(err, clientSecondCall) {
+          if (err) return done(err);
+          assert.strictEqual(wsdl.open_wsdl.callCount, 2);
+          done();
+        });
+      });
+    });
+  });
+
+  it('should use the provided WSDL cache', function(done) {
+    /** @type {IWSDLCache} */
+    var dummyCache = {
+      has: function () {},
+      get: function () {},
+      set: function () {},
+    };
+    sandbox.stub(dummyCache, 'has');
+    sandbox.stub(dummyCache, 'get');
+    sandbox.stub(dummyCache, 'set');
+    dummyCache.has.returns(false);
+    var options = {
+      wsdlCache: dummyCache,
+    };
+    soap.createClient(wsdlUri, options, function(err, clientFirstCall) {
+      assert.strictEqual(dummyCache.has.callCount, 1);
+      assert.strictEqual(dummyCache.get.callCount, 0);
+      assert.strictEqual(dummyCache.set.callCount, 1);
+      // cache miss
+      assert.strictEqual(wsdl.open_wsdl.callCount, 1);
+
+      var cacheEntry = dummyCache.set.firstCall.args;
+      assert.deepStrictEqual(cacheEntry[0], wsdlUri);
+
+      var cachedWSDL = cacheEntry[1];
+      assert.ok(cachedWSDL instanceof wsdl.WSDL);
+      assert.deepStrictEqual(clientFirstCall.wsdl, cachedWSDL);
+
+      sandbox.reset();
+      dummyCache.has.returns(true);
+      dummyCache.get.returns(cachedWSDL);
+
+      soap.createClient(wsdlUri, options, function(err, clientSecondCall) {
+        // hits cache
+        assert.strictEqual(wsdl.open_wsdl.callCount, 0);
+        assert.strictEqual(dummyCache.has.callCount, 1);
+        assert.strictEqual(dummyCache.get.callCount, 1);
+        assert.deepStrictEqual(dummyCache.get.firstCall.args, [wsdlUri]);
+        assert.strictEqual(dummyCache.set.callCount, 0);
+        assert.deepStrictEqual(clientSecondCall.wsdl, cachedWSDL);
+        done();
+      });
+    });
+  });
+});