diff --git a/src/wp-content/themes/twentyeleven/header.php b/src/wp-content/themes/twentyeleven/header.php
index e27cac9316..39cbe89c11 100644
--- a/src/wp-content/themes/twentyeleven/header.php
+++ b/src/wp-content/themes/twentyeleven/header.php
@@ -73,6 +73,7 @@ if ( is_singular() && get_option( 'thread_comments' ) ) {
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="hfeed">
 	<header id="branding" role="banner">
 			<hgroup>
diff --git a/src/wp-content/themes/twentyfifteen/header.php b/src/wp-content/themes/twentyfifteen/header.php
index 63b0437771..41a1e8df7f 100644
--- a/src/wp-content/themes/twentyfifteen/header.php
+++ b/src/wp-content/themes/twentyfifteen/header.php
@@ -22,6 +22,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="hfeed site">
 	<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'twentyfifteen' ); ?></a>
 
diff --git a/src/wp-content/themes/twentyfourteen/header.php b/src/wp-content/themes/twentyfourteen/header.php
index 1de76b341f..88071ec9b9 100644
--- a/src/wp-content/themes/twentyfourteen/header.php
+++ b/src/wp-content/themes/twentyfourteen/header.php
@@ -31,6 +31,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="hfeed site">
 	<?php if ( get_header_image() ) : ?>
 	<div id="site-header">
diff --git a/src/wp-content/themes/twentynineteen/header.php b/src/wp-content/themes/twentynineteen/header.php
index 53827f8ed5..868a521944 100644
--- a/src/wp-content/themes/twentynineteen/header.php
+++ b/src/wp-content/themes/twentynineteen/header.php
@@ -20,6 +20,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="site">
 	<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'twentynineteen' ); ?></a>
 
diff --git a/src/wp-content/themes/twentyseventeen/header.php b/src/wp-content/themes/twentyseventeen/header.php
index 27148be6d4..0ac11c30ec 100644
--- a/src/wp-content/themes/twentyseventeen/header.php
+++ b/src/wp-content/themes/twentyseventeen/header.php
@@ -23,6 +23,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="site">
 	<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'twentyseventeen' ); ?></a>
 
diff --git a/src/wp-content/themes/twentysixteen/header.php b/src/wp-content/themes/twentysixteen/header.php
index f264ac2cd7..a5cfee6a47 100644
--- a/src/wp-content/themes/twentysixteen/header.php
+++ b/src/wp-content/themes/twentysixteen/header.php
@@ -22,6 +22,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="site">
 	<div class="site-inner">
 		<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'twentysixteen' ); ?></a>
diff --git a/src/wp-content/themes/twentyten/header.php b/src/wp-content/themes/twentyten/header.php
index 1a4b35afea..23a186340a 100644
--- a/src/wp-content/themes/twentyten/header.php
+++ b/src/wp-content/themes/twentyten/header.php
@@ -60,6 +60,7 @@ if ( is_singular() && get_option( 'thread_comments' ) ) {
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="wrapper" class="hfeed">
 	<div id="header">
 		<div id="masthead">
diff --git a/src/wp-content/themes/twentythirteen/header.php b/src/wp-content/themes/twentythirteen/header.php
index 31fbfaba07..dee665689b 100644
--- a/src/wp-content/themes/twentythirteen/header.php
+++ b/src/wp-content/themes/twentythirteen/header.php
@@ -31,6 +31,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+	<?php wp_body_open(); ?>
 	<div id="page" class="hfeed site">
 		<header id="masthead" class="site-header" role="banner">
 			<a class="home-link" href="<?php echo esc_url( home_url( '/' ) ); ?>" title="<?php echo esc_attr( get_bloginfo( 'name', 'display' ) ); ?>" rel="home">
diff --git a/src/wp-content/themes/twentytwelve/header.php b/src/wp-content/themes/twentytwelve/header.php
index 107c0a1850..f8ff59907b 100644
--- a/src/wp-content/themes/twentytwelve/header.php
+++ b/src/wp-content/themes/twentytwelve/header.php
@@ -32,6 +32,7 @@
 </head>
 
 <body <?php body_class(); ?>>
+<?php wp_body_open(); ?>
 <div id="page" class="hfeed site">
 	<header id="masthead" class="site-header" role="banner">
 		<hgroup>
diff --git a/src/wp-includes/general-template.php b/src/wp-includes/general-template.php
index 837770f519..1923c79b48 100644
--- a/src/wp-includes/general-template.php
+++ b/src/wp-includes/general-template.php
@@ -2751,6 +2751,22 @@ function wp_footer() {
 	do_action( 'wp_footer' );
 }
 
+/**
+ * Fire the wp_body_open action.
+ *
+ * * See {@see 'wp_body_open'}.
+ *
+ * @since 5.2.0
+ */
+function wp_body_open() {
+	/**
+	 * Triggered after the opening <body> tag.
+	 *
+	 * @since 5.2.0
+	 */
+	do_action( 'wp_body_open' );
+}
+
 /**
  * Display the links to the general feeds.
  *
