diff --git a/src/wp-includes/class-wp-roles.php b/src/wp-includes/class-wp-roles.php
index b7558748db..a665191f4a 100644
--- a/src/wp-includes/class-wp-roles.php
+++ b/src/wp-includes/class-wp-roles.php
@@ -127,6 +127,15 @@ class WP_Roles {
 			$this->role_objects[$role] = new WP_Role( $role, $this->roles[$role]['capabilities'] );
 			$this->role_names[$role] = $this->roles[$role]['name'];
 		}
+
+		/**
+		 * After the roles have been initialized, allow plugins to add their own roles.
+		 *
+		 * @since 4.7.0
+		 *
+		 * @param WP_Roles A reference to the WP_Roles object.
+		 */
+		do_action( 'wp_roles_init', $this );
 	}
 
 	/**
@@ -136,28 +145,12 @@ class WP_Roles {
 	 * after switching wpdb to a new site ID.
 	 *
 	 * @since 3.5.0
+	 * @deprecated 4.7.0 Use new WP_Roles()
 	 * @access public
 	 */
 	public function reinit() {
-		global $wpdb;
-
-		// There is no need to reinit if using the wp_user_roles global.
-		if ( ! $this->use_db ) {
-			return;
-		}
-
-		// Duplicated from _init() to avoid an extra function call.
-		$this->role_key = $wpdb->get_blog_prefix() . 'user_roles';
-		$this->roles = get_option( $this->role_key );
-		if ( empty( $this->roles ) )
-			return;
-
-		$this->role_objects = array();
-		$this->role_names =  array();
-		foreach ( array_keys( $this->roles ) as $role ) {
-			$this->role_objects[$role] = new WP_Role( $role, $this->roles[$role]['capabilities'] );
-			$this->role_names[$role] = $this->roles[$role]['name'];
-		}
+		__deprecated_function( __METHOD__, '4.7.0', 'new WP_Roles()' );
+		$this->_init();
 	}
 
 	/**
diff --git a/src/wp-includes/ms-blogs.php b/src/wp-includes/ms-blogs.php
index db3e4639c1..9188750386 100644
--- a/src/wp-includes/ms-blogs.php
+++ b/src/wp-includes/ms-blogs.php
@@ -766,7 +766,7 @@ function update_blog_option( $id, $option, $value, $deprecated = null ) {
  * @return true Always returns True.
  */
 function switch_to_blog( $new_blog, $deprecated = null ) {
-	global $wpdb;
+	global $wpdb, $wp_roles;
 
 	$blog_id = get_current_blog_id();
 	if ( empty( $new_blog ) ) {
@@ -822,7 +822,7 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
 	}
 
 	if ( did_action( 'init' ) ) {
-		wp_roles()->reinit();
+		$wp_roles = new WP_Roles();
 		$current_user = wp_get_current_user();
 		$current_user->for_blog( $new_blog );
 	}
@@ -850,7 +850,7 @@ function switch_to_blog( $new_blog, $deprecated = null ) {
  * @return bool True on success, false if we're already on the current blog
  */
 function restore_current_blog() {
-	global $wpdb;
+	global $wpdb, $wp_roles;
 
 	if ( empty( $GLOBALS['_wp_switched_stack'] ) ) {
 		return false;
@@ -896,7 +896,7 @@ function restore_current_blog() {
 	}
 
 	if ( did_action( 'init' ) ) {
-		wp_roles()->reinit();
+		$wp_roles = new WP_Roles();
 		$current_user = wp_get_current_user();
 		$current_user->for_blog( $blog );
 	}
diff --git a/tests/phpunit/tests/user/capabilities.php b/tests/phpunit/tests/user/capabilities.php
index dfb34091ed..0948d88e75 100644
--- a/tests/phpunit/tests/user/capabilities.php
+++ b/tests/phpunit/tests/user/capabilities.php
@@ -41,8 +41,7 @@ class Tests_User_Capabilities extends WP_UnitTestCase {
 		// this will flush everything and reload it from the db
 		unset($GLOBALS['wp_user_roles']);
 		global $wp_roles;
-		if ( is_object( $wp_roles ) )
-			$wp_roles->_init();
+		$wp_roles = new WP_Roles();
 	}
 
 	function _meta_yes_you_can( $can, $key, $post_id, $user_id, $cap, $caps ) {
@@ -1626,4 +1625,33 @@ class Tests_User_Capabilities extends WP_UnitTestCase {
 		$this->assertFalse( current_user_can( 'do_not_allow' ), "Non-logged-in user should not have the do_not_allow capability" );
 	}
 
+	protected $_role_test_wp_roles_role;
+	/**
+	 * @ticket 23016
+	 */
+	public function test_wp_roles_init_action() {
+		$this->_role_test_wp_roles_init = array(
+			'role' => 'test_wp_roles_init',
+			'info' => array(
+				'name' => 'Test WP Roles Init',
+				'capabilities' => array( 'testing_magic' => true ),
+			),
+		);
+		add_action( 'wp_roles_init', array( $this, '_hook_wp_roles_init' ), 10, 1 );
+
+		$wp_roles = new WP_Roles();
+
+		remove_action( 'wp_roles_init', array( $this, '_hook_wp_roles_init' ) );
+
+		$expected = new WP_Role( $this->_role_test_wp_roles_init['role'], $this->_role_test_wp_roles_init['info']['capabilities'] );
+
+		$role = $wp_roles->get_role( $this->_role_test_wp_roles_init['role'] );
+
+		$this->assertEquals( $expected, $role );
+		$this->assertContains( $this->_role_test_wp_roles_init['info']['name'], $wp_roles->role_names );
+	}
+
+	public function _hook_wp_roles_init( $wp_roles ) {
+		$wp_roles->add_role( $this->_role_test_wp_roles_init['role'], $this->_role_test_wp_roles_init['info']['name'], $this->_role_test_wp_roles_init['info']['capabilities'] );
+	}
 }
diff --git a/tests/phpunit/tests/user/multisite.php b/tests/phpunit/tests/user/multisite.php
index 698c6ffcd6..f6856844df 100644
--- a/tests/phpunit/tests/user/multisite.php
+++ b/tests/phpunit/tests/user/multisite.php
@@ -396,6 +396,34 @@ class Tests_Multisite_User extends WP_UnitTestCase {
 
 		$this->assertWPError( $result );
 	}
+
+	/**
+	 * @ticket 23016
+	 */
+	public function test_wp_roles_global_is_reset() {
+		global $wp_roles;
+		$role = 'test_global_is_reset';
+		$role_name = 'Test Global Is Reset';
+		$blog_id = self::factory()->blog->create();
+
+		$wp_roles->add_role( $role, $role_name, array() );
+
+		$this->assertNotEmpty( $wp_roles->get_role( $role ) );
+
+		switch_to_blog( $blog_id );
+
+		$this->assertEmpty( $wp_roles->get_role( $role ) );
+
+		$wp_roles->add_role( $role, $role_name, array() );
+
+		$this->assertNotEmpty( $wp_roles->get_role( $role ) );
+
+		restore_current_blog();
+
+		$this->assertNotEmpty( $wp_roles->get_role( $role ) );
+
+		$wp_roles->remove_role( $role );
+	}
 }
 
 endif ;