diff --git a/src/youtube-video.ts b/src/youtube-video.ts
index f8e3ad6f..606f388a 100644
--- a/src/youtube-video.ts
+++ b/src/youtube-video.ts
@@ -205,16 +205,19 @@ export class YoutubeVideoElement extends HTMLElement {
         if (!YoutubeVideoElement.scriptLoadPromise) {
             YoutubeVideoElement.scriptLoadPromise = new Promise((resolve) => {
                 // NOTE: youtube's iframe api ready only fires once after first script load
-                if (!window.onYouTubeIframeAPIReady) {
-                    YoutubeVideoElement.triggerYoutubeIframeAPIReady = resolve;
-                    window.onYouTubeIframeAPIReady = () => {
-                        window.onYouTubeIframeAPIReady = null;
-                        // once the script loads once, we are guaranteed for it to
-                        // be ready even after destruction of all instances (if consumer
-                        // doesnt mangle with it)
-                        YoutubeVideoElement.triggerYoutubeIframeAPIReady();
-                    };
-                }
+                const originalOnYouTubeIframeAPIReady =
+                    window.onYouTubeIframeAPIReady;
+                YoutubeVideoElement.triggerYoutubeIframeAPIReady = resolve;
+                window.onYouTubeIframeAPIReady = (...args) => {
+                    window.onYouTubeIframeAPIReady = null;
+                    // once the script loads once, we are guaranteed for it to
+                    // be ready even after destruction of all instances (if consumer
+                    // doesnt mangle with it)
+                    YoutubeVideoElement.triggerYoutubeIframeAPIReady();
+                    if (originalOnYouTubeIframeAPIReady) {
+                        originalOnYouTubeIframeAPIReady(...args);
+                    }
+                };
                 return ResourceManager.loadScript(this.scriptPath);
             });
         }
diff --git a/tests/youtube-video-tests.ts b/tests/youtube-video-tests.ts
index 8fbafe3d..5ccc62d7 100644
--- a/tests/youtube-video-tests.ts
+++ b/tests/youtube-video-tests.ts
@@ -67,6 +67,31 @@ describe('Youtube Video Tests', function () {
         window.YT = origYT;
     });
 
+    it('does not override original window.onYouTubeIframeAPIReady if exists', async () => {
+        const onYouTubeIframeAPIReadyStub = sinon.stub();
+        Object.defineProperty(window, 'onYouTubeIframeAPIReady', {
+            get() {
+                return onYouTubeIframeAPIReadyStub;
+            },
+            configurable: true,
+        });
+        var videoEl = document.createElement(
+            'youtube-video'
+        ) as YoutubeVideoElement;
+        videoEl.setAttribute('width', '640');
+        videoEl.setAttribute('height', '360');
+        videoEl.setAttribute(
+            'src',
+            'http://www.youtube.com/watch?v=nOEw9iiopwI'
+        );
+        testContainer.appendChild(videoEl);
+        await videoEl.load(); // wait for API to be ready
+        assert.equal(onYouTubeIframeAPIReadyStub.callCount, 0);
+        window.onYouTubeIframeAPIReady();
+        assert.equal(onYouTubeIframeAPIReadyStub.callCount, 1);
+        testContainer.removeChild(videoEl);
+    });
+
     it('should load proper iFrame player api script when load() is called and remove it from the dom when removed', async function () {
         var videoEl = document.createElement(
             'youtube-video'