diff --git a/extensions/amp-story/1.0/amp-story.js b/extensions/amp-story/1.0/amp-story.js
index be03be1ed702..1039fc2238c2 100644
--- a/extensions/amp-story/1.0/amp-story.js
+++ b/extensions/amp-story/1.0/amp-story.js
@@ -1016,6 +1016,7 @@ export class AmpStory extends AMP.BaseElement {
       .then(() => {
         this.markStoryAsLoaded_();
         this.initializeLiveStory_();
+        this.initializeStoryPlayer_();
       });
 
     // Story is being prerendered: resolve the layoutCallback when the first
@@ -1290,6 +1291,20 @@ export class AmpStory extends AMP.BaseElement {
     activePage.next(opt_isAutomaticAdvance);
   }
 
+  /**
+   * Installs amp-viewer-integration script in case story is inside an
+   * amp-story-player.
+   */
+  initializeStoryPlayer_() {
+    if (this.viewer_.getParam('storyPlayer') !== 'v0') {
+      return;
+    }
+    Services.extensionsFor(this.getAmpDoc().win).installExtensionForDoc(
+      this.getAmpDoc(),
+      'amp-viewer-integration'
+    );
+  }
+
   /**
    * Handles EventType.NO_NEXT_PAGE events.
    * @private
diff --git a/src/amp-story-player.js b/src/amp-story-player.js
index d2048455d0ac..47e95615bcdf 100644
--- a/src/amp-story-player.js
+++ b/src/amp-story-player.js
@@ -129,9 +129,6 @@ export class AmpStoryPlayer {
     this.initializeLoadingListeners_(iframeEl);
     this.rootEl_.appendChild(iframeEl);
 
-    // TODO(#26308): enable messaging when multiple documents are supported.
-    return;
-
     this.initializeHandshake_(story, iframeEl).then(
       messaging => {
         const iframeIdx = findIndex(
@@ -206,10 +203,9 @@ export class AmpStoryPlayer {
    * @private
    */
   layoutIframe_(story, iframe) {
-    // TODO(#26308): enable messaging when multiple documents are supported.
-    // const {href} = this.getEncodedLocation_(story.href);
+    const {href} = this.getEncodedLocation_(story.href);
 
-    iframe.setAttribute('src', story.href);
+    iframe.setAttribute('src', href);
   }
 
   /**
@@ -226,6 +222,7 @@ export class AmpStoryPlayer {
       'amp_js_v': '0.1',
       'visibilityState': 'inactive',
       'origin': url.origin,
+      'storyPlayer': 'v0',
     });
 
     const fragmentParam = getFragment(href);