diff --git a/.eslintrc.json b/.eslintrc.json
index 17f167d..240b092 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,7 +1,7 @@
 {
-  "env": { "browser": true, "commonjs": true },
+  "env": { "browser": true },
   "extends": "eslint:recommended",
-  "parserOptions": { "ecmaVersion": 5 },
+  "parserOptions": { "ecmaVersion": 6, "sourceType": "module" },
   "rules": {
     "block-scoped-var": "error",
     "consistent-return": "error",
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 43f9f20..e16f413 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,6 +16,7 @@ jobs:
       - name: Set up PureScript toolchain
         uses: purescript-contrib/setup-purescript@main
         with:
+          purescript: "unstable"
           purs-tidy: "latest"
 
       - name: Cache PureScript dependencies
@@ -49,8 +50,17 @@ jobs:
       - name: Build the project
         run: npm run build
 
-      - name: Run tests
-        run: npm run test
+#      - name: Run tests
+#        run: npm run test
 
       - name: Check formatting
         run: purs-tidy check src test
+
+      - name: Verify Bower & Pulp
+        run: |
+          npm install bower pulp@16.0.0-0
+          npx bower install
+          npx pulp build -- --censor-lib --strict
+          if [ -d "test" ]; then
+            npx pulp test
+          fi
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 074fa5b..61b3080 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ Notable changes to this project are documented in this file. The format is based
 ## [Unreleased]
 
 Breaking changes:
+- Migrate FFI to ES modules (#79 by @i-am-the-slime and @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index 14a8e4b..8f11a23 100644
--- a/bower.json
+++ b/bower.json
@@ -16,18 +16,18 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-datetime": "^5.0.0",
-    "purescript-fixed-points": "^6.0.0",
-    "purescript-lists": "^6.0.0",
-    "purescript-numbers": "^8.0.0",
-    "purescript-parsing": "^7.0.0",
-    "purescript-prelude": "^5.0.0",
-    "purescript-transformers": "^5.0.0"
+    "purescript-datetime": "master",
+    "purescript-fixed-points": "main",
+    "purescript-lists": "master",
+    "purescript-numbers": "master",
+    "purescript-parsing": "main",
+    "purescript-prelude": "master",
+    "purescript-transformers": "master"
   },
   "devDependencies": {
-    "purescript-aff": "^6.0.0",
-    "purescript-assert": "^5.0.0",
-    "purescript-console": "^5.0.0",
-    "purescript-effect": "^3.0.0"
+    "purescript-aff": "main",
+    "purescript-assert": "master",
+    "purescript-console": "master",
+    "purescript-effect": "master"
   }
 }
diff --git a/packages.dhall b/packages.dhall
index 11cc28c..582d6d3 100644
--- a/packages.dhall
+++ b/packages.dhall
@@ -1,5 +1,4 @@
 let upstream =
-      https://github.com/purescript/package-sets/releases/download/psc-0.14.3-20210722/packages.dhall sha256:1ceb43aa59436bf5601bac45f6f3781c4e1f0e4c2b8458105b018e5ed8c30f8c
+      https://raw.githubusercontent.com/purescript/package-sets/prepare-0.15/src/packages.dhall
 
 in  upstream
-  with parsing.version = "v7.0.0"
diff --git a/spago.dhall b/spago.dhall
index faa4bc7..cda9ac8 100644
--- a/spago.dhall
+++ b/spago.dhall
@@ -21,7 +21,6 @@
   , "parsing"
   , "partial"
   , "prelude"
-  , "psci-support"
   , "strings"
   , "transformers"
   , "tuples"
diff --git a/src/Data/Formatter/Number.js b/src/Data/Formatter/Number.js
index ae12239..15a3ff0 100644
--- a/src/Data/Formatter/Number.js
+++ b/src/Data/Formatter/Number.js
@@ -1,7 +1,7 @@
-"use strict";
-
 // Converts a number to a string of the nearest integer _without_ appending ".0"
 // (like `show` for `Number`) or clamping to +/- 2 billion (like when working
 // with `Int`). This is important for performance compared to other means of
 // showing an integer potentially larger than +/- 2 billion.
-exports.showNumberAsInt = function (n) { return Math.round(n).toString(); };
+export function showNumberAsInt(n) {
+  return Math.round(n).toString();
+}