diff --git a/wp-includes/class-wp-xmlrpc-server.php b/wp-includes/class-wp-xmlrpc-server.php
index c684e32698..898a322ff7 100644
--- a/wp-includes/class-wp-xmlrpc-server.php
+++ b/wp-includes/class-wp-xmlrpc-server.php
@@ -4756,20 +4756,26 @@ class wp_xmlrpc_server extends IXR_Server {
 		$post_author = $postdata['post_author'];
 
 		// Only set the post_author if one is set.
-		if ( isset($content_struct['wp_author_id']) && ($user->ID != $content_struct['wp_author_id']) ) {
-			switch ( $post_type ) {
-				case 'post':
-					if ( !current_user_can('edit_others_posts') )
-						return new IXR_Error( 401, __( 'You are not allowed to change the post author as this user.' ) );
-					break;
-				case 'page':
-					if ( !current_user_can('edit_others_pages') )
-						return new IXR_Error( 401, __( 'You are not allowed to change the page author as this user.' ) );
-					break;
-				default:
-					return new IXR_Error( 401, __( 'Invalid post type' ) );
+		if ( isset( $content_struct['wp_author_id'] ) ) {
+			// Check permissions if attempting to switch author to or from another user.
+			if ( $user->ID != $content_struct['wp_author_id'] || $user->ID != $post_author ) {
+				switch ( $post_type ) {
+					case 'post':
+						if ( ! current_user_can( 'edit_others_posts' ) ) {
+							return new IXR_Error( 401, __( 'You are not allowed to change the post author as this user.' ) );
+						}
+						break;
+					case 'page':
+						if ( ! current_user_can( 'edit_others_pages' ) ) {
+							return new IXR_Error( 401, __( 'You are not allowed to change the page author as this user.' ) );
+						}
+						break;
+					default:
+						return new IXR_Error( 401, __( 'Invalid post type' ) );
+						break;
+				}
+				$post_author = $content_struct['wp_author_id'];
 			}
-			$post_author = $content_struct['wp_author_id'];
 		}
 
 		if ( isset($content_struct['mt_allow_comments']) ) {
diff --git a/wp-includes/version.php b/wp-includes/version.php
index a9d2b1079f..238eee5272 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.2-beta3-31982';
+$wp_version = '4.2-beta3-31983';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.