diff --git a/package.json b/package.json
index a142e22a..a98733d4 100644
--- a/package.json
+++ b/package.json
@@ -49,7 +49,7 @@
   "dependencies": {
     "aes-js": "^3.1.2",
     "another-json": "^0.2.0",
-    "bs58": "^4.0.1",
+    "base-x": "^3.0.8",
     "olm": "https://packages.matrix.org/npm/olm/olm-3.1.4.tgz"
   }
 }
diff --git a/scripts/post-install.mjs b/scripts/post-install.mjs
index 43177fd6..77df95f3 100644
--- a/scripts/post-install.mjs
+++ b/scripts/post-install.mjs
@@ -75,11 +75,11 @@ async function populateLib() {
         path.join(modulesDir, 'another-json/another-json.js'),
         path.join(libDir, "another-json/index.js")
     );
-    // transpile bs58 to esm
-    await fs.mkdir(path.join(libDir, "bs58/"));
+    // transpile base-x to esm
+    await fs.mkdir(path.join(libDir, "base-x/"));
     await commonjsToESM(
-        path.join(modulesDir, 'bs58/index.js'),
-        path.join(libDir, "bs58/index.js")
+        path.join(modulesDir, 'base-x/src/index.js'),
+        path.join(libDir, "base-x/index.js")
     );
     // transpile aesjs to esm
     await fs.mkdir(path.join(libDir, "aes-js/"));
diff --git a/src/utils/base-encoding.js b/src/utils/base-encoding.js
new file mode 100644
index 00000000..611ec043
--- /dev/null
+++ b/src/utils/base-encoding.js
@@ -0,0 +1,25 @@
+/*
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import base from "../../lib/base-x/index.js";
+
+// Dictionaries come from https://github.com/cryptocoinjs/base-x/, MIT licenced.
+const BASE58 = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
+const BASE64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+
+export const base58 = base(BASE58);
+export const base64 = base(BASE64); 
diff --git a/yarn.lock b/yarn.lock
index c3b84f26..60e500c1 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -945,7 +945,7 @@ balanced-match@^1.0.0:
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
   integrity sha1-ibTRmasr7kneFk6gK4nORi1xt2c=
 
-base-x@^3.0.2:
+base-x@^3.0.8:
   version "3.0.8"
   resolved "https://registry.yarnpkg.com/base-x/-/base-x-3.0.8.tgz#1e1106c2537f0162e8b52474a557ebb09000018d"
   integrity sha512-Rl/1AWP4J/zRrk54hhlxH4drNxPJXYUaKffODVI53/dAsV4t9fBxyxYKAVPU1XBHxYwOWP9h9H0hM2MVw4YfJA==
@@ -975,13 +975,6 @@ browserslist@^4.12.0, browserslist@^4.8.5:
     escalade "^3.0.2"
     node-releases "^1.1.60"
 
-bs58@^4.0.1:
-  version "4.0.1"
-  resolved "https://registry.yarnpkg.com/bs58/-/bs58-4.0.1.tgz#be161e76c354f6f788ae4071f63f34e8c4f0a42a"
-  integrity sha1-vhYedsNU9veIrkBx9j806MTwpCo=
-  dependencies:
-    base-x "^3.0.2"
-
 builtin-modules@^3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/builtin-modules/-/builtin-modules-3.1.0.tgz#aad97c15131eb76b65b50ef208e7584cd76a7484"