diff --git a/src/applications/phame/controller/PhameLiveController.php b/src/applications/phame/controller/PhameLiveController.php
index b5b1984816..472f73c8c1 100644
--- a/src/applications/phame/controller/PhameLiveController.php
+++ b/src/applications/phame/controller/PhameLiveController.php
@@ -1,234 +1,235 @@
 <?php
 
 abstract class PhameLiveController extends PhameController {
 
   private $isExternal;
   private $isLive;
   private $blog;
   private $post;
 
   public function shouldAllowPublic() {
     return true;
   }
 
   protected function getIsExternal() {
     return $this->isExternal;
   }
 
   protected function getIsLive() {
     return $this->isLive;
   }
 
   protected function getBlog() {
     return $this->blog;
   }
 
   protected function getPost() {
     return $this->post;
   }
 
   protected function setupLiveEnvironment() {
     $request = $this->getRequest();
     $viewer = $this->getViewer();
 
     $site = $request->getSite();
     $blog_id = $request->getURIData('blogID');
     $post_id = $request->getURIData('id');
 
     if ($site instanceof PhameBlogSite) {
       // This is a live page on a custom domain. We already looked up the blog
       // in the Site handler by examining the domain, so we don't need to do
       // more lookups.
 
       $blog = $site->getBlog();
       $is_external = true;
       $is_live = true;
     } else if ($blog_id) {
       // This is a blog detail view, an internal blog live view, or an
       // internal post live view The internal post detail view is handled
       // below.
 
       $is_external = false;
       if ($request->getURIData('live')) {
         $is_live = true;
       } else {
         $is_live = false;
       }
 
       $blog_query = id(new PhameBlogQuery())
         ->setViewer($viewer)
         ->needProfileImage(true)
         ->needHeaderImage(true)
         ->withIDs(array($blog_id));
 
       // If this is a live view, only show active blogs.
       if ($is_live) {
         $blog_query->withStatuses(
           array(
             PhameBlog::STATUS_ACTIVE,
           ));
       }
 
       $blog = $blog_query->executeOne();
       if (!$blog) {
         $this->isExternal = $is_external;
         $this->isLive = $is_live;
         return new Aphront404Response();
       }
 
     } else {
       // This is a post detail page, so we'll figure out the blog by loading
       // the post first.
       $is_external = false;
       $is_live = false;
       $blog = null;
     }
 
     $this->isExternal = $is_external;
     $this->isLive = $is_live;
 
     if (strlen($post_id)) {
       $post_query = id(new PhamePostQuery())
         ->setViewer($viewer)
         ->needHeaderImage(true)
         ->withIDs(array($post_id));
 
-      if ($blog) {
-        $post_query->withBlogPHIDs(array($blog->getPHID()));
-      }
-
       // Only show published posts on external domains.
       if ($is_external) {
         $post_query->withVisibility(
           array(PhameConstants::VISIBILITY_PUBLISHED));
       }
 
       $post = $post_query->executeOne();
       if (!$post) {
         // Not a valid Post
         $this->blog = $blog;
         return new Aphront404Response();
       }
 
       // If this is a post detail page, the URI didn't come with a blog ID,
       // so fill that in.
       if (!$blog) {
         $blog = $post->getBlog();
       }
     } else {
       $post = null;
     }
 
     $this->blog = $blog;
     $this->post = $post;
 
     // If we have a post, canonicalize the URI to the post's current slug and
-    // redirect the user if it isn't correct.
+    // redirect the user if it isn't correct. Likewise, canonicalize the URI
+    // if the blog ID is wrong. See T13353.
     if ($post) {
       $slug = $request->getURIData('slug');
-      if ($post->getSlug() != $slug) {
+
+      $wrong_slug = ($post->getSlug() !== $slug);
+      $wrong_blog = ($post->getBlog()->getID() !== $blog->getID());
+
+      if ($wrong_slug || $wrong_blog) {
         if ($is_live) {
           if ($is_external) {
             $uri = $post->getExternalLiveURI();
           } else {
             $uri = $post->getInternalLiveURI();
           }
         } else {
           $uri = $post->getViewURI();
         }
 
         $response = id(new AphrontRedirectResponse())
           ->setURI($uri);
 
         if ($is_external) {
           $response->setIsExternal(true);
         }
 
         return $response;
       }
     }
 
     return null;
   }
 
   protected function buildApplicationCrumbs() {
     $blog = $this->getBlog();
     $post = $this->getPost();
 
     $is_live = $this->getIsLive();
     $is_external = $this->getIsExternal();
 
     // If this is an external view, don't put the "Phame" crumb or the
     // "Blogs" crumb into the crumbs list.
     if ($is_external) {
       $crumbs = new PHUICrumbsView();
       // Link back to parent site
       if ($blog->getParentSite() && $blog->getParentDomain()) {
         $crumbs->addTextCrumb(
           $blog->getParentSite(),
           $blog->getExternalParentURI());
       }
     } else {
       $crumbs = parent::buildApplicationCrumbs();
       $crumbs->addTextCrumb(
         pht('Blogs'),
         $this->getApplicationURI('blog/'));
     }
 
     $crumbs->setBorder(true);
 
     if ($blog) {
       if ($post) {
         if ($is_live) {
           if ($is_external) {
             $blog_uri = $blog->getExternalLiveURI();
           } else {
             $blog_uri = $blog->getInternalLiveURI();
           }
         } else {
           $blog_uri = $blog->getViewURI();
         }
       } else {
         $blog_uri = null;
       }
 
       $crumbs->addTextCrumb($blog->getName(), $blog_uri);
     }
 
     if ($post) {
       if (!$is_external) {
         $crumbs->addTextCrumb('J'.$post->getID());
       }
     }
 
     return $crumbs;
   }
 
   public function willSendResponse(AphrontResponse $response) {
     if ($this->getIsExternal()) {
       if ($response instanceof Aphront404Response) {
         $page = $this->newPage()
           ->setCrumbs($this->buildApplicationCrumbs());
 
         $response = id(new Phame404Response())
           ->setPage($page);
       }
     }
 
     return parent::willSendResponse($response);
   }
 
   public function newPage() {
     $page = parent::newPage();
 
     if ($this->getIsLive()) {
       $page
         ->addClass('phame-live-view')
         ->setShowChrome(false)
         ->setShowFooter(false);
     }
 
     return $page;
   }
 
 }