diff --git a/wp-includes/html-api/class-wp-html-open-elements.php b/wp-includes/html-api/class-wp-html-open-elements.php
index 210492ab9a..aee5dccfb0 100644
--- a/wp-includes/html-api/class-wp-html-open-elements.php
+++ b/wp-includes/html-api/class-wp-html-open-elements.php
@@ -715,7 +715,7 @@ class WP_HTML_Open_Elements {
 		}
 
 		if ( null !== $this->push_handler ) {
-			( $this->push_handler )( $item );
+			call_user_func( $this->push_handler, $item );
 		}
 	}
 
@@ -763,7 +763,7 @@ class WP_HTML_Open_Elements {
 		}
 
 		if ( null !== $this->pop_handler ) {
-			( $this->pop_handler )( $item );
+			call_user_func( $this->pop_handler, $item );
 		}
 	}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c5b807e2df..f76a3a8757 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '7.0-alpha-61623';
+$wp_version = '7.0-alpha-61624';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.