diff --git a/src/wp-includes/formatting.php b/src/wp-includes/formatting.php
index e690948ea2..38cd23c95e 100644
--- a/src/wp-includes/formatting.php
+++ b/src/wp-includes/formatting.php
@@ -2465,7 +2465,7 @@ function force_balance_tags( $text ) {
 	// WP bug fix for LOVE <3 (and other situations with '<' before a number)
 	$text = preg_replace( '#<([0-9]{1})#', '&lt;$1', $text );
 
-	while ( preg_match( '/<(\/?[\w:]*)\s*([^>]*)>/', $text, $regex ) ) {
+	while ( preg_match( '/<(\/?[\w:\-]*)\s*([^>]*)>/', $text, $regex ) ) {
 		$newtext .= $tagqueue;
 
 		$i = strpos( $text, $regex[0] );
diff --git a/tests/phpunit/tests/formatting/balanceTags.php b/tests/phpunit/tests/formatting/balanceTags.php
index 783c320780..f479d84d26 100644
--- a/tests/phpunit/tests/formatting/balanceTags.php
+++ b/tests/phpunit/tests/formatting/balanceTags.php
@@ -221,4 +221,42 @@ class Tests_Formatting_BalanceTags extends WP_UnitTestCase {
 		}
 	}
 
+	/**
+	 * Get custom element data.
+	 *
+	 * @return array Data.
+	 */
+	public function get_custom_element_data() {
+		return array(
+			array(
+				'<my-custom-element>Test</my-custom-element>',
+				'<my-custom-element>Test</my-custom-element>',
+			),
+			array(
+				'<my-custom-element>Test',
+				'<my-custom-element>Test</my-custom-element>',
+			),
+			array(
+				'Test</my-custom-element>',
+				'Test',
+			),
+			array(
+				'</my-custom-element>Test',
+				'Test',
+			),
+		);
+	}
+
+	/**
+	 * Test custom elements.
+	 *
+	 * @ticket 47014
+	 * @dataProvider get_custom_element_data()
+	 *
+	 * @param string $source   Source.
+	 * @param string $expected Expected.
+	 */
+	public function test_custom_elements( $source, $expected ) {
+		$this->assertEquals( $expected, balanceTags( $source, true ) );
+	}
 }