diff --git a/wp-includes/canonical.php b/wp-includes/canonical.php
index 42d6dcf44a..b73b9f72f2 100644
--- a/wp-includes/canonical.php
+++ b/wp-includes/canonical.php
@@ -409,6 +409,17 @@ function redirect_canonical( $requested_url = null, $do_redirect = true ) {
 			}
 
 			$redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
+		} elseif ( is_singular() && empty( get_query_var( 'name' ) ) && $post_id ) {
+			/*
+			 * Redirect example.org/%post_id%/ to canonical url.
+			 * @ticket 12456
+			 */
+			$redirect_url      = get_permalink( $post_id );
+			$redirect['query'] = _remove_qs_args_if_not_in_url(
+				$redirect['query'],
+				array( 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ),
+				$redirect_url
+			);
 		}
 
 		// Paging and feeds.
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 95468f7c2d..ba52abdd13 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.5-alpha-47936';
+$wp_version = '5.5-alpha-47937';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.