diff -u b/composer.lock b/composer.lock
--- b/composer.lock
+++ b/composer.lock
@@ -734,12 +734,12 @@
             "source": {
                 "type": "git",
                 "url": "https://github.com/Masterminds/html5-php.git",
-                "reference": "b39dd885966dea2d3d33509af505f4ecef2f6343"
+                "reference": "398ebb68c9395a67858d230d0610aa3676bebdc7"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/Masterminds/html5-php/zipball/b39dd885966dea2d3d33509af505f4ecef2f6343",
-                "reference": "b39dd885966dea2d3d33509af505f4ecef2f6343",
+                "url": "https://api.github.com/repos/Masterminds/html5-php/zipball/398ebb68c9395a67858d230d0610aa3676bebdc7",
+                "reference": "398ebb68c9395a67858d230d0610aa3676bebdc7",
                 "shasum": ""
             },
             "require": {
diff -u b/core/modules/filter/src/Tests/FilterUnitTest.php b/core/modules/filter/src/Tests/FilterUnitTest.php
--- b/core/modules/filter/src/Tests/FilterUnitTest.php
+++ b/core/modules/filter/src/Tests/FilterUnitTest.php
@@ -890,9 +890,8 @@
     $f = Html::normalize('<div></div>');
     $this->assertEqual($f, '<div></div>', "HTML corrector -- Do not transform empty tags to a single closed tag if the tag's content model is not EMPTY.");
 
-    // @todo Blocked on https://github.com/Masterminds/html5-php/issues/68
-    //$f = Html::normalize('<p>line1<br/><hr/>line2</p>');
-    //$this->assertEqual($f, '<p>line1<br /></p><hr />line2', 'HTML corrector -- Move non-inline elements outside of inline containers.');
+    $f = Html::normalize('<p>line1<br/><hr/>line2</p>');
+    $this->assertEqual($f, '<p>line1<br/></p><hr/>line2', 'HTML corrector -- Move non-inline elements outside of inline containers.');
 
     $f = Html::normalize('<p>line1<div>line2</div></p>');
     $this->assertEqual($f, '<p>line1</p><div>line2</div>', 'HTML corrector -- Move non-inline elements outside of inline containers.');