diff --git a/playground/package-lock.json b/playground/package-lock.json
index 3828c8c20..08a7b3040 100644
--- a/playground/package-lock.json
+++ b/playground/package-lock.json
@@ -2484,12 +2484,6 @@
         }
       }
     },
-    "core-js": {
-      "version": "2.6.2",
-      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.2.tgz",
-      "integrity": "sha512-NdBPF/RVwPW6jr0NCILuyN9RiqLo2b1mddWHkUL+VnvcB7dzlnBJ1bXYntjpTGOgkZiiLWj2JxmOr7eGE3qK6g==",
-      "dev": true
-    },
     "core-util-is": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.2.tgz",
@@ -4001,7 +3995,8 @@
           "version": "2.1.1",
           "resolved": false,
           "integrity": "sha1-w7M6te42DYbg5ijwRorn7yfWVN8=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "aproba": {
           "version": "1.2.0",
@@ -4025,13 +4020,15 @@
           "version": "1.0.0",
           "resolved": false,
           "integrity": "sha1-ibTRmasr7kneFk6gK4nORi1xt2c=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "brace-expansion": {
           "version": "1.1.11",
           "resolved": false,
           "integrity": "sha512-iCuPHDFgrHX7H2vEI/5xpz07zSHB00TpugqhmYtVmMO6518mCuRMoOYFldEBl0g187ufozdaHgWKcYFb61qGiA==",
           "dev": true,
+          "optional": true,
           "requires": {
             "balanced-match": "^1.0.0",
             "concat-map": "0.0.1"
@@ -4048,19 +4045,22 @@
           "version": "1.1.0",
           "resolved": false,
           "integrity": "sha1-DQcLTQQ6W+ozovGkDi7bPZpMz3c=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "concat-map": {
           "version": "0.0.1",
           "resolved": false,
           "integrity": "sha1-2Klr13/Wjfd5OnMDajug1UBdR3s=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "console-control-strings": {
           "version": "1.1.0",
           "resolved": false,
           "integrity": "sha1-PXz0Rk22RG6mRL9LOVB/mFEAjo4=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "core-util-is": {
           "version": "1.0.2",
@@ -4191,7 +4191,8 @@
           "version": "2.0.3",
           "resolved": false,
           "integrity": "sha1-Yzwsg+PaQqUC9SRmAiSA9CCCYd4=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "ini": {
           "version": "1.3.5",
@@ -4205,6 +4206,7 @@
           "resolved": false,
           "integrity": "sha1-754xOG8DGn8NZDr4L95QxFfvAMs=",
           "dev": true,
+          "optional": true,
           "requires": {
             "number-is-nan": "^1.0.0"
           }
@@ -4221,6 +4223,7 @@
           "resolved": false,
           "integrity": "sha512-yJHVQEhyqPLUTgt9B83PXu6W3rx4MvvHvSUvToogpwoGDOUQ+yDrR0HRot+yOCdCO7u4hX3pWft6kWBBcqh0UA==",
           "dev": true,
+          "optional": true,
           "requires": {
             "brace-expansion": "^1.1.7"
           }
@@ -4229,13 +4232,15 @@
           "version": "0.0.8",
           "resolved": false,
           "integrity": "sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "minipass": {
           "version": "2.2.4",
           "resolved": false,
           "integrity": "sha512-hzXIWWet/BzWhYs2b+u7dRHlruXhwdgvlTMDKC6Cb1U7ps6Ac6yQlR39xsbjWJE377YTCtKwIXIpJ5oP+j5y8g==",
           "dev": true,
+          "optional": true,
           "requires": {
             "safe-buffer": "^5.1.1",
             "yallist": "^3.0.0"
@@ -4256,6 +4261,7 @@
           "resolved": false,
           "integrity": "sha1-MAV0OOrGz3+MR2fzhkjWaX11yQM=",
           "dev": true,
+          "optional": true,
           "requires": {
             "minimist": "0.0.8"
           }
@@ -4344,7 +4350,8 @@
           "version": "1.0.1",
           "resolved": false,
           "integrity": "sha1-CXtgK1NCKlIsGvuHkDGDNpQaAR0=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "object-assign": {
           "version": "4.1.1",
@@ -4358,6 +4365,7 @@
           "resolved": false,
           "integrity": "sha1-WDsap3WWHUsROsF9nFC6753Xa9E=",
           "dev": true,
+          "optional": true,
           "requires": {
             "wrappy": "1"
           }
@@ -4453,7 +4461,8 @@
           "version": "5.1.1",
           "resolved": false,
           "integrity": "sha512-kKvNJn6Mm93gAczWVJg7wH+wGYWNrDHdWvpUmHyEsgCtIwwo3bqPtV4tR5tuPaUhTOo/kvhVwd8XwwOllGYkbg==",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "safer-buffer": {
           "version": "2.1.2",
@@ -4495,6 +4504,7 @@
           "resolved": false,
           "integrity": "sha1-EYvfW4zcUaKn5w0hHgfisLmxB9M=",
           "dev": true,
+          "optional": true,
           "requires": {
             "code-point-at": "^1.0.0",
             "is-fullwidth-code-point": "^1.0.0",
@@ -4516,6 +4526,7 @@
           "resolved": false,
           "integrity": "sha1-ajhfuIU9lS1f8F0Oiq+UJ43GPc8=",
           "dev": true,
+          "optional": true,
           "requires": {
             "ansi-regex": "^2.0.0"
           }
@@ -4564,13 +4575,15 @@
           "version": "1.0.2",
           "resolved": false,
           "integrity": "sha1-tSQ9jz7BqjXxNkYFvA0QNuMKtp8=",
-          "dev": true
+          "dev": true,
+          "optional": true
         },
         "yallist": {
           "version": "3.0.2",
           "resolved": false,
           "integrity": "sha1-hFK0u36Dx8GI2AQcGoN8dz1ti7k=",
-          "dev": true
+          "dev": true,
+          "optional": true
         }
       }
     },
@@ -7308,14 +7321,10 @@
       "dev": true
     },
     "preload-webpack-plugin": {
-      "version": "3.0.0-beta.3",
-      "resolved": "https://registry.npmjs.org/preload-webpack-plugin/-/preload-webpack-plugin-3.0.0-beta.3.tgz",
-      "integrity": "sha512-pIRna/JagOd+ci64d84SfDH4bjKsM632OQ/4JIBk7Q8Kr6VH2X+7q5q3HrTilKpMzzO3ib9kC7rs1B0KXJTa6Q==",
-      "dev": true,
-      "requires": {
-        "core-js": "^2.5.7",
-        "url-parse": "^1.4.3"
-      }
+      "version": "3.0.0-beta.4",
+      "resolved": "https://registry.npmjs.org/preload-webpack-plugin/-/preload-webpack-plugin-3.0.0-beta.4.tgz",
+      "integrity": "sha512-6hhh0AswCbp/U4EPVN4fbK2wiDkXhmgjjgEYEmXa21UYwjYzCIgh3ZRMXM21ZPLfbQGpdFuSL3zFslU+edjpwg==",
+      "dev": true
     },
     "prelude-ls": {
       "version": "1.1.2",
diff --git a/playground/package.json b/playground/package.json
index 7e0eeab0c..cece784d3 100644
--- a/playground/package.json
+++ b/playground/package.json
@@ -37,7 +37,7 @@
     "keymaster": "1.6.2",
     "mini-css-extract-plugin": "0.5.0",
     "optimize-css-assets-webpack-plugin": "5.0.1",
-    "preload-webpack-plugin": "3.0.0-beta.3",
+    "preload-webpack-plugin": "3.0.0-beta.4",
     "style-loader": "0.23.0",
     "url-loader": "1.1.2",
     "url-search-params": "1.1.0",