diff --git a/package.json b/package.json
index 3686966870..a18186ef6e 100644
--- a/package.json
+++ b/package.json
@@ -72,12 +72,10 @@
     "fuse.js": "^2.2.0",
     "gemini-scrollbar": "github:matrix-org/gemini-scrollbar#91e1e566",
     "gfm.css": "^1.1.1",
-    "glob": "^5.0.14",
     "glob-to-regexp": "^0.4.1",
     "highlight.js": "^9.15.8",
     "html-entities": "^1.2.1",
     "is-ip": "^2.0.0",
-    "isomorphic-fetch": "^2.2.1",
     "linkifyjs": "^2.1.6",
     "lodash": "^4.17.14",
     "lolex": "4.2",
@@ -88,7 +86,6 @@
     "prop-types": "^15.5.8",
     "qrcode-react": "^0.1.16",
     "qs": "^6.6.0",
-    "querystring": "^0.2.0",
     "react": "^16.9.0",
     "react-addons-css-transition-group": "15.6.2",
     "react-beautiful-dnd": "^4.0.1",
@@ -101,7 +98,6 @@
     "url": "^0.11.0",
     "velocity-animate": "^1.5.2",
     "what-input": "^5.2.6",
-    "whatwg-fetch": "^1.1.1",
     "zxcvbn": "^4.4.2"
   },
   "devDependencies": {
@@ -137,11 +133,11 @@
     "estree-walker": "^0.5.0",
     "file-loader": "^3.0.1",
     "flow-parser": "^0.57.3",
+    "glob": "^5.0.14",
     "jest": "^24.9.0",
     "matrix-mock-request": "^1.2.3",
     "matrix-react-test-utils": "^0.2.2",
     "react-test-renderer": "^16.9.0",
-    "require-json": "0.0.1",
     "rimraf": "^2.4.3",
     "source-map-loader": "^0.2.3",
     "stylelint": "^9.10.1",
diff --git a/src/autocomplete/DuckDuckGoProvider.js b/src/autocomplete/DuckDuckGoProvider.js
index ca1b1478cc..8cff83554a 100644
--- a/src/autocomplete/DuckDuckGoProvider.js
+++ b/src/autocomplete/DuckDuckGoProvider.js
@@ -19,7 +19,6 @@ limitations under the License.
 import React from 'react';
 import { _t } from '../languageHandler';
 import AutocompleteProvider from './AutocompleteProvider';
-import 'whatwg-fetch';
 
 import {TextualCompletion} from './Components';
 import type {SelectionRange} from "./Autocompleter";
diff --git a/src/components/views/elements/AppTile.js b/src/components/views/elements/AppTile.js
index 4b586b1553..b12ace708d 100644
--- a/src/components/views/elements/AppTile.js
+++ b/src/components/views/elements/AppTile.js
@@ -17,7 +17,7 @@ limitations under the License.
 */
 
 import url from 'url';
-import qs from 'querystring';
+import qs from 'qs';
 import React, {createRef} from 'react';
 import PropTypes from 'prop-types';
 import {MatrixClientPeg} from '../../../MatrixClientPeg';
diff --git a/src/utils/DecryptFile.js b/src/utils/DecryptFile.js
index b87b723ed7..f5a1b0aa62 100644
--- a/src/utils/DecryptFile.js
+++ b/src/utils/DecryptFile.js
@@ -17,8 +17,6 @@ limitations under the License.
 
 // Pull in the encryption lib so that we can decrypt attachments.
 import encrypt from 'browser-encrypt-attachment';
-// Pull in a fetch polyfill so we can download encrypted attachments.
-import 'isomorphic-fetch';
 // Grab the client so that we can turn mxc:// URLs into https:// URLS.
 import {MatrixClientPeg} from '../MatrixClientPeg';
 
diff --git a/yarn.lock b/yarn.lock
index 81602b4e3d..db405d2480 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -4869,7 +4869,7 @@ isobject@^3.0.0, isobject@^3.0.1:
   resolved "https://registry.yarnpkg.com/isobject/-/isobject-3.0.1.tgz#4e431e92b11a9731636aa1f9c8d1ccbcfdab78df"
   integrity sha1-TkMekrEalzFjaqH5yNHMvP2reN8=
 
-isomorphic-fetch@^2.1.1, isomorphic-fetch@^2.2.1:
+isomorphic-fetch@^2.1.1:
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/isomorphic-fetch/-/isomorphic-fetch-2.2.1.tgz#611ae1acf14f5e81f729507472819fe9733558a9"
   integrity sha1-YRrhrPFPXoH3KVB0coGf6XM1WKk=
@@ -6995,7 +6995,7 @@ querystring-es3@^0.2.0:
   resolved "https://registry.yarnpkg.com/querystring-es3/-/querystring-es3-0.2.1.tgz#9ec61f79049875707d69414596fd907a4d711e73"
   integrity sha1-nsYfeQSYdXB9aUFFlv2Qek1xHnM=
 
-querystring@0.2.0, querystring@^0.2.0:
+querystring@0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/querystring/-/querystring-0.2.0.tgz#b209849203bb25df820da756e747005878521620"
   integrity sha1-sgmEkgO7Jd+CDadW50cAWHhSFiA=
@@ -7473,11 +7473,6 @@ require-directory@^2.1.1:
   resolved "https://registry.yarnpkg.com/require-directory/-/require-directory-2.1.1.tgz#8c64ad5fd30dab1c976e2344ffe7f792a6a6df42"
   integrity sha1-jGStX9MNqxyXbiNE/+f3kqam30I=
 
-require-json@0.0.1:
-  version "0.0.1"
-  resolved "https://registry.yarnpkg.com/require-json/-/require-json-0.0.1.tgz#3c8914f93d7442de8cbf4e681ac62a72aa3367fe"
-  integrity sha1-PIkU+T10Qt6Mv05oGsYqcqozZ/4=
-
 require-main-filename@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-1.0.1.tgz#97f717b69d48784f5f526a6c5aa8ffdda055a4d1"
@@ -9014,11 +9009,6 @@ whatwg-fetch@^0.9.0:
   resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-0.9.0.tgz#0e3684c6cb9995b43efc9df03e4c365d95fd9cc0"
   integrity sha1-DjaExsuZlbQ+/J3wPkw2XZX9nMA=
 
-whatwg-fetch@^1.1.1:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/whatwg-fetch/-/whatwg-fetch-1.1.1.tgz#ac3c9d39f320c6dce5339969d054ef43dd333319"
-  integrity sha1-rDydOfMgxtzlM5lp0FTvQ90zMxk=
-
 whatwg-mimetype@^2.1.0, whatwg-mimetype@^2.2.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/whatwg-mimetype/-/whatwg-mimetype-2.3.0.tgz#3d4b1e0312d2079879f826aff18dbeeca5960fbf"