reverted:
--- b/composer.json
+++ a/composer.json
@@ -5,8 +5,7 @@
     "license": "GPL-2.0+",
     "require": {
         "composer/installers": "^1.0.24",
+        "wikimedia/composer-merge-plugin": "^1.4"
-        "wikimedia/composer-merge-plugin": "^1.4",
-        "drupal/jsonapi": "^1.3"
     },
     "replace": {
         "drupal/core": "^8.5"
reverted:
--- b/composer.lock
+++ a/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
+    "content-hash": "97de1708c79f6205a295cfc9808c0c72",
-    "content-hash": "2fdbff82cf3c865c64db8c4d27421c34",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -636,68 +636,6 @@
             "time": "2014-09-09T13:34:57+00:00"
         },
         {
-            "name": "drupal/jsonapi",
-            "version": "1.3.0",
-            "source": {
-                "type": "git",
-                "url": "https://git.drupal.org/project/jsonapi",
-                "reference": "8.x-1.3"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://ftp.drupal.org/files/projects/jsonapi-8.x-1.3.zip",
-                "reference": "8.x-1.3",
-                "shasum": "cd3df010a305097e8fee08a2d1777bd6ad58c64a"
-            },
-            "require": {
-                "drupal/core": "^8.2"
-            },
-            "require-dev": {
-                "justinrainbow/json-schema": "^4.1"
-            },
-            "type": "drupal-module",
-            "extra": {
-                "branch-alias": {
-                    "dev-1.x": "1.x-dev"
-                },
-                "drupal": {
-                    "version": "8.x-1.3",
-                    "datestamp": "1505680144",
-                    "security-coverage": {
-                        "status": "covered",
-                        "message": "Covered by Drupal's security advisory policy"
-                    }
-                }
-            },
-            "notification-url": "https://packages.drupal.org/8/downloads",
-            "license": [
-                "GPL-2.0+"
-            ],
-            "authors": [
-                {
-                    "name": "Wim Leers",
-                    "homepage": "https://www.drupal.org/user/99777"
-                },
-                {
-                    "name": "dawehner",
-                    "homepage": "https://www.drupal.org/user/99340"
-                },
-                {
-                    "name": "e0ipso",
-                    "homepage": "https://www.drupal.org/user/550110"
-                },
-                {
-                    "name": "gabesullice",
-                    "homepage": "https://www.drupal.org/user/2287430"
-                }
-            ],
-            "description": "Provides a JSON API standards-compliant API for accessing and manipulating Drupal content and configuration entities.",
-            "homepage": "https://www.drupal.org/project/jsonapi",
-            "support": {
-                "source": "http://cgit.drupalcode.org/jsonapi"
-            }
-        },
-        {
             "name": "easyrdf/easyrdf",
             "version": "0.9.1",
             "source": {