diff --git a/wp-includes/rest-api.php b/wp-includes/rest-api.php
index c831fed7ec..fd6dc3e5f9 100644
--- a/wp-includes/rest-api.php
+++ b/wp-includes/rest-api.php
@@ -337,6 +337,14 @@ function get_rest_url( $blog_id = null, $path = '/', $scheme = 'rest' ) {
 		}
 	}
 
+	if ( is_admin() && force_ssl_admin() ) {
+		// In this situation the home URL may be http:, and `is_ssl()` may be
+		// false, but the admin is served over https: (one way or another), so
+		// REST API usage will be blocked by browsers unless it is also served
+		// over HTTPS.
+		$url = set_url_scheme( $url, 'https' );
+	}
+
 	/**
 	 * Filters the REST URL.
 	 *
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 1016cfa141..304578f60c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-beta2-40842';
+$wp_version = '4.8-beta2-40843';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.