diff --git a/wp-includes/class-wp-editor.php b/wp-includes/class-wp-editor.php
index e1e36abe8d..baefc7c696 100644
--- a/wp-includes/class-wp-editor.php
+++ b/wp-includes/class-wp-editor.php
@@ -569,10 +569,12 @@ final class _WP_Editors {
 		$baseurl = self::$baseurl;
 
 		if ( $tmce_on ) {
-			if ( $compressed )
+			if ( $compressed ) {
 				echo "<script type='text/javascript' src='{$baseurl}/wp-tinymce.php?c=1&amp;$version'></script>\n";
-			else
+			} else {
 				echo "<script type='text/javascript' src='{$baseurl}/tiny_mce.js?$version'></script>\n";
+				echo "<script type='text/javascript' src='{$baseurl}/wp-tinymce-schema.js?$version'></script>\n";
+			}
 
 			if ( 'en' != self::$mce_locale && isset($lang) )
 				echo "<script type='text/javascript'>\n$lang\n</script>\n";
diff --git a/wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js b/wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js
index 3c4dc9b20a..e5a512d631 100644
--- a/wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js
+++ b/wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js
@@ -135,21 +135,8 @@
 				}
 			});
 
-			// Add obsolete HTML attributes that are still in use.
+			// Extend <object> and <embed> (#WP22790)
 			ed.onPreInit.add(function(ed) {
-				// The commonAttr are from TinyMCE 3.5.7 getHTML5()
-				// Obsolete attributes are from TinyMCE 3.5.7 getHTML4()
-				var commonAttr = 'id|accesskey|class|dir|draggable|item|hidden|itemprop|role|spellcheck|style|subject|title|onclick|ondblclick|onmousedown|onmouseup|onmouseover|onmousemove|onmouseout|onkeypress|onkeydown|onkeyup',
-					tdAttr = commonAttr + '|abbr|axis|headers|scope|rowspan|colspan|char|charoff|align|valign|halign|nowrap|bgcolor|width|height';
-				// Obsolete table attributes
-				ed.schema.addValidElements('table['+commonAttr+'|summary|width|border|frame|rules|cellspacing|cellpadding|align|bgcolor]');
-				// Obsolete tr attributes
-				ed.schema.addValidElements('tr['+commonAttr+'|align|char|charoff|valign|halign|bgcolor]');
-				// Obsolete td and th attributes
-				ed.schema.addValidElements('td['+tdAttr+'],th['+tdAttr+']');
-				// Adds "name" for <a>
-				ed.schema.addValidElements('a['+commonAttr+'|href|target|ping|rel|media|type|name]');
-				// Extend <object> and <embed>
 				ed.schema.addValidElements('object[*],param[id|name|value|valuetype|type],embed[*]');
 				ed.schema.addValidChildren('object[*]');
 			});
diff --git a/wp-includes/js/tinymce/wp-tinymce-schema.js b/wp-includes/js/tinymce/wp-tinymce-schema.js
index afd03d225d..2115ffc80b 100644
--- a/wp-includes/js/tinymce/wp-tinymce-schema.js
+++ b/wp-includes/js/tinymce/wp-tinymce-schema.js
@@ -1,5 +1,7 @@
 /**
- * Schema.js
+ * TinyMCE Schema.js
+ *
+ * Duck-punched by WordPress core to support a sane schema superset.
  *
  * Copyright, Moxiecode Systems AB
  * Released under LGPL License.
@@ -319,6 +321,59 @@
 		return html4;
 	};
 
+	/**
+	 * WordPress Core
+	 *
+	 * Returns a schema that is the result of a deep merge between the HTML5
+	 * and HTML4 schemas.
+	 */
+	function getSaneSchema() {
+		var cachedMapCache = mapCache,
+			html5, html4;
+
+		if ( mapCache.sane )
+			return mapCache.sane;
+
+		// Bust the mapCache so we're not dealing with the other schema objects.
+		mapCache = {};
+		html5 = getHTML5();
+		html4 = getHTML4();
+		mapCache = cachedMapCache;
+
+		each( html4, function( html4settings, tag ) {
+			var html5settings = html5[ tag ],
+				difference = [];
+
+			// Merge tags missing in HTML5 mode.
+			if ( ! html5settings ) {
+				html5[ tag ] = html4settings;
+				return;
+			}
+
+			// Merge attributes missing from this HTML5 tag.
+			each( html4settings.attributes, function( attribute, key ) {
+				if ( ! html5settings.attributes[ key ] )
+					html5settings.attributes[ key ] = attribute;
+			});
+
+			// Merge any missing attributes into the attributes order.
+			each( html4settings.attributesOrder, function( key ) {
+				if ( -1 === tinymce.inArray( html5settings.attributesOrder, key ) )
+					difference.push( key );
+			});
+
+			html5settings.attributesOrder = html5settings.attributesOrder.concat( difference );
+
+			// Merge children missing from this HTML5 tag.
+			each( html4settings.children, function( child, key ) {
+				if ( ! html5settings.children[ key ] )
+					html5settings.children[ key ] = child;
+			});
+		});
+
+		return mapCache.sane = html5;
+	}
+
 	/**
 	 * Schema validator class.
 	 *
@@ -368,7 +423,11 @@
 		};
 
 		settings = settings || {};
-		schemaItems = settings.schema == "html5" ? getHTML5() : getHTML4();
+
+		/**
+		 * WordPress core uses a sane schema in place of the default "HTML5" schema.
+		 */
+		schemaItems = settings.schema == "html5" ? getSaneSchema() : getHTML4();
 
 		// Allow all elements and attributes if verify_html is set to false
 		if (settings.verify_html === false)
diff --git a/wp-includes/js/tinymce/wp-tinymce.php b/wp-includes/js/tinymce/wp-tinymce.php
index c2cf33ca34..83a003d720 100644
--- a/wp-includes/js/tinymce/wp-tinymce.php
+++ b/wp-includes/js/tinymce/wp-tinymce.php
@@ -33,5 +33,6 @@ if ( isset($_GET['c']) && 1 == $_GET['c'] && isset($_SERVER['HTTP_ACCEPT_ENCODIN
 	echo $file;
 } else {
 	echo get_file($basepath . '/tiny_mce.js');
+	echo get_file($basepath . '/wp-tinymce-schema.js');
 }
 exit;