diff --git a/.travis.yml b/.travis.yml
index d0d0a879f..700ac85ca 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,6 +10,7 @@ cache:
 node_js:
   - '8'
   - '10'
+  - '12'
 
 env:
   matrix:
diff --git a/package-lock.json b/package-lock.json
index ad4a5c032..41510b12d 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -4840,6 +4840,12 @@
       "resolved": "https://registry.npmjs.org/copy-descriptor/-/copy-descriptor-0.1.1.tgz",
       "integrity": "sha1-Z29us8OZl8LuGsOpJP1hJHSPV40="
     },
+    "core-js": {
+      "version": "2.6.8",
+      "resolved": "https://registry.npmjs.org/core-js/-/core-js-2.6.8.tgz",
+      "integrity": "sha512-RWlREFU74TEkdXzyl1bka66O3kYp8jeTXrvJZDzVVMH8AiHUSOFpL1yfhQJ+wHocAm1m+4971W1PPzfLuCv1vg==",
+      "dev": true
+    },
     "core-js-compat": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/core-js-compat/-/core-js-compat-3.0.1.tgz",
diff --git a/package.json b/package.json
index e00411902..c14fdf6ed 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
     "babel-jest": "^24.7.1",
     "babel-loader": "^8.0.5",
     "clone": "^2.1.1",
+    "core-js": "^2.6.8",
     "coveralls": "^3.0.3",
     "cross-env": "^5.2.0",
     "dedent": "^0.7.0",
diff --git a/packages/remark-images-download/__tests__/index.js b/packages/remark-images-download/__tests__/index.js
index 4799a8340..df86bc4c0 100644
--- a/packages/remark-images-download/__tests__/index.js
+++ b/packages/remark-images-download/__tests__/index.js
@@ -441,8 +441,8 @@ describe('mock server tests', () => {
     const render = renderFactory({httpRequestTimeout: 500})
 
     return render(file).then(vfile => {
-      expect(firstMsg(vfile)).toBe(
-        'getaddrinfo ENOTFOUND doesnotexist-kqwtkk78.com doesnotexist-kqwtkk78.com:80')
+      expect(firstMsg(vfile)).toContain(
+        'getaddrinfo ENOTFOUND doesnotexist-kqwtkk78.com')
       expect(vfile.contents).toBe(html)
     })
   })