diff --git a/src/wp-content/themes/twentyeleven/functions.php b/src/wp-content/themes/twentyeleven/functions.php
index 7dc3bf52ef..f17bf729f3 100644
--- a/src/wp-content/themes/twentyeleven/functions.php
+++ b/src/wp-content/themes/twentyeleven/functions.php
@@ -79,8 +79,15 @@ if ( ! function_exists( 'twentyeleven_setup' ) ) :
 		 * If you're building a theme based on Twenty Eleven, use
 		 * a find and replace to change 'twentyeleven' to the name
 		 * of your theme in all the template files.
+		 *
+		 * Manual loading of text domain is not required after the introduction of
+		 * just in time translation loading in WordPress version 4.6.
+		 *
+		 * @ticket 58318
 		 */
-		load_theme_textdomain( 'twentyeleven', get_template_directory() . '/languages' );
+		if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+			load_theme_textdomain( 'twentyeleven', get_template_directory() . '/languages' );
+		}
 
 		// This theme styles the visual editor with editor-style.css to match the theme style.
 		add_editor_style();
diff --git a/src/wp-content/themes/twentyfifteen/functions.php b/src/wp-content/themes/twentyfifteen/functions.php
index 25f5a22eeb..0091b2828c 100644
--- a/src/wp-content/themes/twentyfifteen/functions.php
+++ b/src/wp-content/themes/twentyfifteen/functions.php
@@ -57,9 +57,17 @@ if ( ! function_exists( 'twentyfifteen_setup' ) ) :
 		 * Make theme available for translation.
 		 * Translations can be filed at WordPress.org. See: https://translate.wordpress.org/projects/wp-themes/twentyfifteen
 		 * If you're building a theme based on twentyfifteen, use a find and replace
-		 * to change 'twentyfifteen' to the name of your theme in all the template files
+		 * to change 'twentyfifteen' to the name of your theme in all the template files.
+		 *
+		 * Manual loading of text domain is not required after the introduction of
+		 * just in time translation loading in WordPress version 4.6.
+		 *
+		 * @ticket 58318
 		 */
-		load_theme_textdomain( 'twentyfifteen' );
+
+		if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+			load_theme_textdomain( 'twentyfifteen' );
+		}
 
 		// Add default posts and comments RSS feed links to head.
 		add_theme_support( 'automatic-feed-links' );
diff --git a/src/wp-content/themes/twentyfourteen/functions.php b/src/wp-content/themes/twentyfourteen/functions.php
index 4441910d67..798a5fd8fa 100644
--- a/src/wp-content/themes/twentyfourteen/functions.php
+++ b/src/wp-content/themes/twentyfourteen/functions.php
@@ -64,8 +64,15 @@ if ( ! function_exists( 'twentyfourteen_setup' ) ) :
 		 * If you're building a theme based on Twenty Fourteen, use a find and
 		 * replace to change 'twentyfourteen' to the name of your theme in all
 		 * template files.
+		 *
+		 * Manual loading of text domain is not required after the introduction of
+		 * just in time translation loading in WordPress version 4.6.
+		 *
+		 * @ticket 58318
 		 */
-		load_theme_textdomain( 'twentyfourteen' );
+		if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+			load_theme_textdomain( 'twentyfourteen' );
+		}
 
 		/*
 		 * This theme styles the visual editor to resemble the theme style.
diff --git a/src/wp-content/themes/twentynineteen/functions.php b/src/wp-content/themes/twentynineteen/functions.php
index 99f7c21e6e..92199f09a0 100644
--- a/src/wp-content/themes/twentynineteen/functions.php
+++ b/src/wp-content/themes/twentynineteen/functions.php
@@ -26,13 +26,6 @@ if ( ! function_exists( 'twentynineteen_setup' ) ) :
 	 * as indicating support for post thumbnails.
 	 */
 	function twentynineteen_setup() {
-		/*
-		 * Make theme available for translation.
-		 * Translations can be filed in the /languages/ directory.
-		 * If you're building a theme based on Twenty Nineteen, use a find and replace
-		 * to change 'twentynineteen' to the name of your theme in all the template files.
-		 */
-		load_theme_textdomain( 'twentynineteen', get_template_directory() . '/languages' );
 
 		// Add default posts and comments RSS feed links to head.
 		add_theme_support( 'automatic-feed-links' );
diff --git a/src/wp-content/themes/twentyseventeen/functions.php b/src/wp-content/themes/twentyseventeen/functions.php
index 7709d63980..436e683971 100644
--- a/src/wp-content/themes/twentyseventeen/functions.php
+++ b/src/wp-content/themes/twentyseventeen/functions.php
@@ -25,13 +25,6 @@ if ( version_compare( $GLOBALS['wp_version'], '4.7-alpha', '<' ) ) {
  * as indicating support for post thumbnails.
  */
 function twentyseventeen_setup() {
-	/*
-	 * Make theme available for translation.
-	 * Translations can be filed at WordPress.org. See: https://translate.wordpress.org/projects/wp-themes/twentyseventeen
-	 * If you're building a theme based on Twenty Seventeen, use a find and replace
-	 * to change 'twentyseventeen' to the name of your theme in all the template files.
-	 */
-	load_theme_textdomain( 'twentyseventeen' );
 
 	// Add default posts and comments RSS feed links to head.
 	add_theme_support( 'automatic-feed-links' );
diff --git a/src/wp-content/themes/twentysixteen/functions.php b/src/wp-content/themes/twentysixteen/functions.php
index 1125bc72bd..d66fbbad48 100644
--- a/src/wp-content/themes/twentysixteen/functions.php
+++ b/src/wp-content/themes/twentysixteen/functions.php
@@ -49,9 +49,16 @@ if ( ! function_exists( 'twentysixteen_setup' ) ) :
 		 * Make theme available for translation.
 		 * Translations can be filed at WordPress.org. See: https://translate.wordpress.org/projects/wp-themes/twentysixteen
 		 * If you're building a theme based on Twenty Sixteen, use a find and replace
-		 * to change 'twentysixteen' to the name of your theme in all the template files
+		 * to change 'twentysixteen' to the name of your theme in all the template files.
+		 *
+		 * Manual loading of text domain is not required after the introduction of
+		 * just in time translation loading in WordPress version 4.6.
+		 *
+		 * @ticket 58318
 		 */
-		load_theme_textdomain( 'twentysixteen' );
+		if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+			load_theme_textdomain( 'twentysixteen' );
+		}
 
 		// Add default posts and comments RSS feed links to head.
 		add_theme_support( 'automatic-feed-links' );
diff --git a/src/wp-content/themes/twentyten/functions.php b/src/wp-content/themes/twentyten/functions.php
index 8bda350d40..fa9cb12cc1 100644
--- a/src/wp-content/themes/twentyten/functions.php
+++ b/src/wp-content/themes/twentyten/functions.php
@@ -128,8 +128,15 @@ if ( ! function_exists( 'twentyten_setup' ) ) :
 		/*
 		 * Make theme available for translation.
 		 * Translations can be filed in the /languages/ directory.
+		 *
+		 * Manual loading of text domain is not required after the introduction of
+		 * just in time translation loading in WordPress version 4.6.
+		 *
+		 * @ticket 58318
 		 */
-		load_theme_textdomain( 'twentyten', get_template_directory() . '/languages' );
+		if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+			load_theme_textdomain( 'twentyten', get_template_directory() . '/languages' );
+		}
 
 		// This theme uses wp_nav_menu() in one location.
 		register_nav_menus(
diff --git a/src/wp-content/themes/twentythirteen/functions.php b/src/wp-content/themes/twentythirteen/functions.php
index 72301b4a53..5ad412971b 100644
--- a/src/wp-content/themes/twentythirteen/functions.php
+++ b/src/wp-content/themes/twentythirteen/functions.php
@@ -75,8 +75,15 @@ function twentythirteen_setup() {
 	 * If you're building a theme based on Twenty Thirteen, use a find and
 	 * replace to change 'twentythirteen' to the name of your theme in all
 	 * template files.
+	 *
+	 * Manual loading of text domain is not required after the introduction of
+	 * just in time translation loading in WordPress version 4.6.
+	 *
+	 * @ticket 58318
 	 */
-	load_theme_textdomain( 'twentythirteen' );
+	if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+		load_theme_textdomain( 'twentythirteen' );
+	}
 
 	/*
 	 * This theme styles the visual editor to resemble the theme style,
diff --git a/src/wp-content/themes/twentytwelve/functions.php b/src/wp-content/themes/twentytwelve/functions.php
index de535ac5f2..8021515f69 100644
--- a/src/wp-content/themes/twentytwelve/functions.php
+++ b/src/wp-content/themes/twentytwelve/functions.php
@@ -51,8 +51,15 @@ function twentytwelve_setup() {
 	 * Translations can be filed at WordPress.org. See: https://translate.wordpress.org/projects/wp-themes/twentytwelve
 	 * If you're building a theme based on Twenty Twelve, use a find and replace
 	 * to change 'twentytwelve' to the name of your theme in all the template files.
+	 *
+	 * Manual loading of text domain is not required after the introduction of
+	 * just in time translation loading in WordPress version 4.6.
+	 *
+	 * @ticket 58318
 	 */
-	load_theme_textdomain( 'twentytwelve' );
+	if ( version_compare( $GLOBALS['wp_version'], '4.6', '<' ) ) {
+		load_theme_textdomain( 'twentytwelve' );
+	}
 
 	// This theme styles the visual editor with editor-style.css to match the theme style.
 	add_editor_style();
diff --git a/src/wp-content/themes/twentytwenty/functions.php b/src/wp-content/themes/twentytwenty/functions.php
index b721b991e1..65085df485 100644
--- a/src/wp-content/themes/twentytwenty/functions.php
+++ b/src/wp-content/themes/twentytwenty/functions.php
@@ -111,14 +111,6 @@ function twentytwenty_theme_support() {
 		)
 	);
 
-	/*
-	 * Make theme available for translation.
-	 * Translations can be filed in the /languages/ directory.
-	 * If you're building a theme based on Twenty Twenty, use a find and replace
-	 * to change 'twentytwenty' to the name of your theme in all the template files.
-	 */
-	load_theme_textdomain( 'twentytwenty' );
-
 	// Add support for full and wide align images.
 	add_theme_support( 'align-wide' );
 
diff --git a/src/wp-content/themes/twentytwentyone/functions.php b/src/wp-content/themes/twentytwentyone/functions.php
index 3279c66e71..ff8c958be7 100644
--- a/src/wp-content/themes/twentytwentyone/functions.php
+++ b/src/wp-content/themes/twentytwentyone/functions.php
@@ -27,13 +27,6 @@ if ( ! function_exists( 'twenty_twenty_one_setup' ) ) {
 	 * @return void
 	 */
 	function twenty_twenty_one_setup() {
-		/*
-		 * Make theme available for translation.
-		 * Translations can be filed in the /languages/ directory.
-		 * If you're building a theme based on Twenty Twenty-One, use a find and replace
-		 * to change 'twentytwentyone' to the name of your theme in all the template files.
-		 */
-		load_theme_textdomain( 'twentytwentyone', get_template_directory() . '/languages' );
 
 		// Add default posts and comments RSS feed links to head.
 		add_theme_support( 'automatic-feed-links' );