diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index d860784356..b4ea8bd0fc 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -751,13 +751,24 @@ function _wp_specialchars( $string, $quote_style = ENT_NOQUOTES, $charset = fals
 		$quote_style = ENT_NOQUOTES;
 	}
 
-	if ( ! $double_encode ) {
-		// Guarantee every &entity; is valid, convert &garbage; into &garbage;
-		// This is required for PHP < 5.4.0 because ENT_HTML401 flag is unavailable.
-		$string = wp_kses_normalize_entities( $string );
-	}
+	// Handle double encoding ourselves
+	if ( $double_encode ) {
+		$string = @htmlspecialchars( $string, $quote_style, $charset );
+	} else {
+		// Decode &amp; into &
+		$string = wp_specialchars_decode( $string, $_quote_style );
 
-	$string = @htmlspecialchars( $string, $quote_style, $charset, $double_encode );
+		// Guarantee every &entity; is valid or re-encode the &
+		$string = wp_kses_normalize_entities( $string );
+
+		// Now re-encode everything except &entity;
+		$string = preg_split( '/(&#?x?[0-9a-z]+;)/i', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
+
+		for ( $i = 0, $c = count( $string ); $i < $c; $i += 2 ) {
+			$string[$i] = @htmlspecialchars( $string[$i], $quote_style, $charset );
+		}
+		$string = implode( '', $string );
+	}
 
 	// Backwards compatibility
 	if ( 'single' === $_quote_style )
diff --git a/tests/phpunit/tests/formatting/EscAttr.php b/tests/phpunit/tests/formatting/EscAttr.php
index 55ca837d05..35ea2f54a5 100644
--- a/tests/phpunit/tests/formatting/EscAttr.php
+++ b/tests/phpunit/tests/formatting/EscAttr.php
@@ -26,7 +26,7 @@ class Tests_Formatting_EscAttr extends WP_UnitTestCase {
 	}
 
 	function test_esc_attr_amp() {
-		$out = esc_attr( 'foo & bar &baz; &nbsp;' );
-		$this->assertEquals( "foo &amp; bar &amp;baz; &nbsp;", $out );
+		$out = esc_attr( 'foo & bar &baz; &apos;' );
+		$this->assertEquals( "foo &amp; bar &amp;baz; &apos;", $out );
 	}
 }
diff --git a/tests/phpunit/tests/formatting/EscHtml.php b/tests/phpunit/tests/formatting/EscHtml.php
index 14f17dfa8c..101692622e 100644
--- a/tests/phpunit/tests/formatting/EscHtml.php
+++ b/tests/phpunit/tests/formatting/EscHtml.php
@@ -34,7 +34,7 @@ class Tests_Formatting_EscHtml extends WP_UnitTestCase {
 
 	function test_ignores_existing_entities() {
 		$source = '&#038; &#x00A3; &#x22; &amp;';
-		$res = '&#038; &#xA3; &#x22; &amp;';
+		$res = '&amp; &#xA3; &quot; &amp;';
 		$this->assertEquals( $res, esc_html($source) );
 	}
 }
diff --git a/tests/phpunit/tests/formatting/JSEscape.php b/tests/phpunit/tests/formatting/JSEscape.php
index 286bf616e2..6ec3892982 100644
--- a/tests/phpunit/tests/formatting/JSEscape.php
+++ b/tests/phpunit/tests/formatting/JSEscape.php
@@ -23,13 +23,13 @@ class Tests_Formatting_JSEscape extends WP_UnitTestCase {
 	}
 
 	function test_js_escape_amp() {
-		$out = esc_js('foo & bar &baz; &nbsp;');
-		$this->assertEquals("foo &amp; bar &amp;baz; &nbsp;", $out);
+		$out = esc_js('foo & bar &baz; &apos;');
+		$this->assertEquals("foo &amp; bar &amp;baz; &apos;", $out);
 	}
 
 	function test_js_escape_quote_entity() {
 		$out = esc_js('foo &#x27; bar &#39; baz &#x26;');
-		$this->assertEquals("foo \\' bar \\' baz &#x26;", $out);
+		$this->assertEquals("foo \\' bar \\' baz &amp;", $out);
 	}
 
 	function test_js_no_carriage_return() {
diff --git a/tests/phpunit/tests/formatting/WPSpecialchars.php b/tests/phpunit/tests/formatting/WPSpecialchars.php
index ddae7fdefa..6c8765d4db 100644
--- a/tests/phpunit/tests/formatting/WPSpecialchars.php
+++ b/tests/phpunit/tests/formatting/WPSpecialchars.php
@@ -17,10 +17,6 @@ class Tests_Formatting_WPSpecialchars extends WP_UnitTestCase {
 
 		// Allowed entities should be unchanged
 		foreach ( $allowedentitynames as $ent ) {
-			if ( 'apos' == $ent ) {
-				// But for some reason, PHP doesn't allow &apos;
-				continue;
-			}
 			$ent = '&' . $ent . ';';
 			$this->assertEquals( $ent, _wp_specialchars( $ent ) );
 		}
@@ -43,58 +39,4 @@ class Tests_Formatting_WPSpecialchars extends WP_UnitTestCase {
 		$this->assertEquals( '&quot;&#039;hello!&#039;&quot;', _wp_specialchars($source, true) );
 		$this->assertEquals( $source, _wp_specialchars($source) );
 	}
-
-	/**
-	 * Check some of the double-encoding features for entity references.
-	 *
-	 * @ticket 17780
-	 * @dataProvider data_double_encoding
-	 */
-	function test_double_encoding( $input, $output ) {
-		return $this->assertEquals( $output, _wp_specialchars( $input, ENT_NOQUOTES, false, true ) );
-	}
-
-	function data_double_encoding() {
-		return array(
-			array(
-				'This & that, this &amp; that, &#8212; &quot; &QUOT; &Uacute; &nbsp; &#34; &#034; &#0034; &#x00022; &#x22; &dollar; &times;',
-				'This &amp; that, this &amp;amp; that, &amp;#8212; &amp;quot; &amp;QUOT; &amp;Uacute; &amp;nbsp; &amp;#34; &amp;#034; &amp;#0034; &amp;#x00022; &amp;#x22; &amp;dollar; &amp;times;',
-			),
-			array(
-				'&& &&amp; &amp;&amp; &amp;;',
-				'&amp;&amp; &amp;&amp;amp; &amp;amp;&amp;amp; &amp;amp;;',
-			),
-			array(
-				'&garbage; &***; &aaaa; &0000; &####; &;;',
-				'&amp;garbage; &amp;***; &amp;aaaa; &amp;0000; &amp;####; &amp;;;',
-			),
-		);
-	}
-
-	/**
-	 * Check some of the double-encoding features for entity references.
-	 *
-	 * @ticket 17780
-	 * @dataProvider data_no_double_encoding
-	 */
-	function test_no_double_encoding( $input, $output ) {
-		return $this->assertEquals( $output, _wp_specialchars( $input, ENT_NOQUOTES, false, false ) );
-	}
-
-	function data_no_double_encoding() {
-		return array(
-			array(
-				'This & that, this &amp; that, &#8212; &quot; &QUOT; &Uacute; &nbsp; &#34; &#034; &#0034; &#x00022; &#x22; &dollar; &times;',
-				'This &amp; that, this &amp; that, &#8212; &quot; &amp;QUOT; &Uacute; &nbsp; &#034; &#034; &#034; &#x22; &#x22; &amp;dollar; &times;',
-			),
-			array(
-				'&& &&amp; &amp;&amp; &amp;;',
-				'&amp;&amp; &amp;&amp; &amp;&amp; &amp;;',
-			),
-			array(
-				'&garbage; &***; &aaaa; &0000; &####; &;;',
-				'&amp;garbage; &amp;***; &amp;aaaa; &amp;0000; &amp;####; &amp;;;',
-			),
-		);
-	}
 }