diff --git a/core/modules/outside_in/js/off-canvas.iframe.js b/core/modules/outside_in/js/off-canvas.iframe.js
new file mode 100644
index 0000000..30a6067
--- /dev/null
+++ b/core/modules/outside_in/js/off-canvas.iframe.js
@@ -0,0 +1,33 @@
+/**
+ * @file
+ * Drupal's off_canvas_iframe library.
+ */
+
+(function ($, Drupal) {
+  'use strict';
+
+  /**
+   * Ensure that links in the iframe use the correct renderer.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Append the correct _wrapper_format for links in the iframe.
+   */
+  Drupal.behaviors.offCanvasIFrameLinks = {
+    attach: function (context) {
+      var $context = $(context);
+      // Update href for all links not targeting the "_parent".
+      $context.find('a[target!="_parent"]').each(function () {
+        $(this).attr('href', $(this).attr('href') + '?_wrapper_format=drupal_dialog_offcanvas');
+      });
+      $context.find('[data-dialog-renderer="offcanvas"]').each(function () {
+        $(this).removeAttr('data-dialog-renderer');
+        $(this).removeAttr('data-dialog-type');
+
+      });
+
+      // @todo What should happen with off-canvas
+    }
+  };
+})(jQuery, Drupal);
diff --git a/core/modules/outside_in/js/offcanvas.js b/core/modules/outside_in/js/offcanvas.js
index 8cda69d..7b5749d 100644
--- a/core/modules/outside_in/js/offcanvas.js
+++ b/core/modules/outside_in/js/offcanvas.js
@@ -144,4 +144,73 @@
     }
   });
 
+  /**
+   * Add the Off-canvas wrapper format to the path.
+   *
+   * @param {string} path
+   *   The path.
+   * @return {string}
+   *   The appended path.
+   */
+  function addFormatWrapper(path) {
+    if (path.includes('?')) {
+      path += '&';
+    }
+    else {
+      path += '?';
+    }
+    return path + '_wrapper_format=drupal_dialog_offcanvas';
+  }
+
+  /**
+   * Open off-canvas links in an iframe dialog.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   */
+  Drupal.behaviors.offCanvasLinks = {
+    attach: function (context) {
+      if ($('.off-canvas-iframe').length) {
+        // Already in off-canvas iframe do not open any links in the nested
+        // iframe.
+        // @see \Drupal\outside_in\Render\MainContent\OffCanvasRender::renderResponse
+        return;
+      }
+
+      $(context).find('[data-dialog-renderer="offcanvas"]').on('click', function (event) {
+        event.preventDefault();
+
+        var path = addFormatWrapper($(event.currentTarget).attr('href'));
+        if (!$('#drupal-offcanvas').length) {
+          $('<div id="drupal-offcanvas" class="ui-front"><iframe id="iframe-dialog" /></div>').appendTo('body');
+        }
+        var $dialog = $('#drupal-offcanvas');
+        $('#iframe-dialog').attr('src', path);
+        var dialogOptions = {
+          dialogClass: 'ui-dialog-outside-in ui-dialog-offcanvas',
+          modal: false,
+          autoResize: false,
+          resizable: 'w',
+          draggable: false,
+          drupalAutoButtons: false,
+          buttons: []
+        };
+        var dialog = Drupal.dialog($dialog.get(0), dialogOptions);
+
+        $('iframe').on('load', function () {
+          if (!$('.ui-dialog-title').length) {
+            dialog.show();
+          }
+          else {
+            var iframeTitle = document.getElementById('iframe-dialog').contentDocument.title;
+            $('.ui-dialog-title').text(iframeTitle);
+          }
+        });
+
+      });
+
+    }
+  };
+
 })(jQuery, Drupal, Drupal.debounce, Drupal.displace);
diff --git a/core/modules/outside_in/js/outside_in.js b/core/modules/outside_in/js/outside_in.js
index 44dda51..723075c 100644
--- a/core/modules/outside_in/js/outside_in.js
+++ b/core/modules/outside_in/js/outside_in.js
@@ -210,43 +210,6 @@
     attach: function (context) {
 
       $(toggleEditSelector).once('outsidein').on('click.outsidein', toggleEditMode);
-      var $context = $(context);
-
-      $context.find('[data-dialog-renderer="offcanvas"]').on('click', function (event) {
-        event.preventDefault();
-
-        var path = $(event.currentTarget).attr('href') + '&_wrapper_format=drupal_dialog_offcanvas';
-        if (!$('#drupal-offcanvas').length) {
-          $('<div id="drupal-offcanvas" class="ui-front"><iframe id="iframe-dialog" /></div>').appendTo('body');
-        }
-        var $dialog = $('#drupal-offcanvas');
-        $('#iframe-dialog').attr('src', path);
-        var dialogOptions = {
-          dialogClass: 'ui-dialog-outside-in ui-dialog-offcanvas',
-          modal: false,
-          autoResize: false,
-          resizable: 'w',
-          draggable: false,
-          drupalAutoButtons: false,
-          buttons: []
-        };
-        var dialog = Drupal.dialog($dialog.get(0), dialogOptions);
-
-        $('iframe').on('load', function () {
-          if (!$('.ui-dialog-title').length) {
-            dialog.show();
-          }
-          else {
-            var iframeTitle = document.getElementById('iframe-dialog').contentDocument.title;
-            $('.ui-dialog-title').text(iframeTitle);
-          }
-
-
-
-        });
-
-      });
-
     }
   };
 
diff --git a/core/modules/outside_in/outside_in.libraries.yml b/core/modules/outside_in/outside_in.libraries.yml
index ec6228c..ecc75a2 100644
--- a/core/modules/outside_in/outside_in.libraries.yml
+++ b/core/modules/outside_in/outside_in.libraries.yml
@@ -34,3 +34,9 @@ drupal.off_canvas:
     - core/drupal.announce
     - core/drupal.dialog
     - core/drupal.dialog.ajax
+drupal.off_canvas_iframe:
+  version: VERSION
+  js:
+    js/off-canvas.iframe.js: {}
+  dependencies:
+    - core/jquery
diff --git a/core/modules/outside_in/src/Block/BlockEntityOffCanvasForm.php b/core/modules/outside_in/src/Block/BlockEntityOffCanvasForm.php
index 3a6e420..63711b7 100644
--- a/core/modules/outside_in/src/Block/BlockEntityOffCanvasForm.php
+++ b/core/modules/outside_in/src/Block/BlockEntityOffCanvasForm.php
@@ -36,6 +36,7 @@ public function title(BlockInterface $block) {
    */
   public function form(array $form, FormStateInterface $form_state) {
     $form = parent::form($form, $form_state);
+    $form['#attributes']['target'] = '_parent';
 
     // Create link to full block form.
     $query = [];
diff --git a/core/modules/outside_in/src/Render/MainContent/OffCanvasRender.php b/core/modules/outside_in/src/Render/MainContent/OffCanvasRender.php
index 41c2089..37cd741 100644
--- a/core/modules/outside_in/src/Render/MainContent/OffCanvasRender.php
+++ b/core/modules/outside_in/src/Render/MainContent/OffCanvasRender.php
@@ -28,6 +28,17 @@ protected function prepare(array $main_content, Request $request, RouteMatchInte
   /**
    * {@inheritdoc}
    */
+  public function renderResponse(array $main_content, Request $request, RouteMatchInterface $route_match) {
+    $main_content['#attached']['library'][] = 'outside_in/drupal.off_canvas_iframe';
+    // Add a class so that JS can determine if we are currently in the iframe.
+    // @todo Will adding the class always work on the top level?
+    $main_content['#attributes']['class'][] = 'off-canvas-iframe';
+    return parent::renderResponse($main_content, $request, $route_match);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
   public function buildPageTopAndBottom(array &$html) {
     parent::buildPageTopAndBottom($html);
     unset($html['page_top']['toolbar']);
diff --git a/core/modules/outside_in/tests/modules/offcanvas_test/offcanvas_test.routing.yml b/core/modules/outside_in/tests/modules/offcanvas_test/offcanvas_test.routing.yml
index 761693b..abbb7af 100644
--- a/core/modules/outside_in/tests/modules/offcanvas_test/offcanvas_test.routing.yml
+++ b/core/modules/outside_in/tests/modules/offcanvas_test/offcanvas_test.routing.yml
@@ -17,6 +17,7 @@ offcanvas_test.thing1:
 offcanvas_test.thing2:
   path: '/offcanvas-thing2'
   defaults:
+    _title: 'Thing 2'
     _controller: '\Drupal\offcanvas_test\Controller\TestController::thing2'
   requirements:
     _access: 'TRUE'
diff --git a/core/modules/outside_in/tests/modules/offcanvas_test/src/Controller/TestController.php b/core/modules/outside_in/tests/modules/offcanvas_test/src/Controller/TestController.php
index 9ee8e17..2fd9736 100644
--- a/core/modules/outside_in/tests/modules/offcanvas_test/src/Controller/TestController.php
+++ b/core/modules/outside_in/tests/modules/offcanvas_test/src/Controller/TestController.php
@@ -49,7 +49,6 @@ public function linksDisplay() {
         '#type' => 'link',
         '#url' => Url::fromRoute('offcanvas_test.thing1'),
         '#attributes' => [
-          'class' => ['use-ajax'],
           'data-dialog-type' => 'dialog',
           'data-dialog-renderer' => 'offcanvas',
         ],
@@ -64,7 +63,6 @@ public function linksDisplay() {
         '#type' => 'link',
         '#url' => Url::fromRoute('offcanvas_test.thing2'),
         '#attributes' => [
-          'class' => ['use-ajax'],
           'data-dialog-type' => 'dialog',
           'data-dialog-renderer' => 'offcanvas',
           'data-dialog-options' => Json::encode([
@@ -82,7 +80,6 @@ public function linksDisplay() {
         '#type' => 'link',
         '#url' => Url::fromRoute('offcanvas_test.dialog_links'),
         '#attributes' => [
-          'class' => ['use-ajax'],
           'data-dialog-type' => 'dialog',
           'data-dialog-renderer' => 'offcanvas',
         ],
@@ -123,7 +120,6 @@ public function otherDialogLinks() {
           'title' => 'Offcanvas link!',
           'url' => Url::fromRoute('offcanvas_test.thing2'),
           'attributes' => [
-            'class' => ['use-ajax'],
             'data-dialog-type' => 'dialog',
             'data-dialog-renderer' => 'offcanvas',
           ],