diff --git a/.eslintrc.json b/.eslintrc.json
index 65496fa..6dd17f6 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,10 +1,10 @@
 {
   "parserOptions": {
-    "ecmaVersion": 5
+    "ecmaVersion": 6,
+    "sourceType": "module"
   },
   "extends": "eslint:recommended",
   "env": {
-    "commonjs": true,
     "browser": true
   },
   "globals": {
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 063845e..06ed895 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,10 +13,12 @@ jobs:
       - uses: actions/checkout@v2
 
       - uses: purescript-contrib/setup-purescript@main
+        with:
+          purescript: "unstable"
 
-      - uses: actions/setup-node@v1
+      - uses: actions/setup-node@v2
         with:
-          node-version: "10"
+          node-version: "14"
 
       - name: Install dependencies
         run: |
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d60d0e0..a52cba2 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 (#14 by @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index 060778b..7cc1da9 100644
--- a/bower.json
+++ b/bower.json
@@ -13,11 +13,11 @@
     "output"
   ],
   "dependencies": {
-    "purescript-effect": "^3.0.0",
-    "purescript-exceptions": "^5.0.0",
-    "purescript-functions": "^5.0.0",
-    "purescript-maybe": "^5.0.0",
-    "purescript-prelude": "^5.0.0",
-    "purescript-foldable-traversable": "^5.0.0"
+    "purescript-effect": "master",
+    "purescript-exceptions": "master",
+    "purescript-functions": "master",
+    "purescript-maybe": "master",
+    "purescript-prelude": "master",
+    "purescript-foldable-traversable": "master"
   }
 }
diff --git a/package.json b/package.json
index 1c67b54..4ea39f9 100644
--- a/package.json
+++ b/package.json
@@ -6,8 +6,8 @@
   },
   "devDependencies": {
     "eslint": "^7.15.0",
-    "pulp": "^15.0.0",
-    "purescript-psa": "^0.8.0",
+    "pulp": "16.0.0-0",
+    "purescript-psa": "^0.8.2",
     "rimraf": "^3.0.2"
   }
 }
diff --git a/src/Web/Promise/Internal.js b/src/Web/Promise/Internal.js
index 4cc44d7..f3b6e8a 100644
--- a/src/Web/Promise/Internal.js
+++ b/src/Web/Promise/Internal.js
@@ -1,33 +1,34 @@
-"use strict";
-
-exports.new = function(k) {
+const newImpl = function (k) {
   return new Promise(k);
 };
+export { newImpl as new };
 
-exports.then_ = function(k, p) {
+export function then_(k, p) {
   return p.then(k);
-};
+}
 
-exports.catch  = function(k, p) {
+const catchImpl = function (k, p) {
   return p.catch(k);
 };
+export { catchImpl as catch };
 
-exports.finally = function(k, p) {
+const finallyImpl = function (k, p) {
   return p.finally(k);
 };
+export { finallyImpl as finally };
 
-exports.resolve = function(a) {
+export function resolve(a) {
   return Promise.resolve(a);
-};
+}
 
-exports.reject = function(a) {
+export function reject(a) {
   return Promise.reject(a);
-};
+}
 
-exports.all = function(a) {
+export function all(a) {
   return Promise.all(a);
-};
+}
 
-exports.race = function(a) {
+export function race(a) {
   return Promise.race(a);
-};
+}
diff --git a/src/Web/Promise/Rejection.js b/src/Web/Promise/Rejection.js
index 3c8ea75..83dcb67 100644
--- a/src/Web/Promise/Rejection.js
+++ b/src/Web/Promise/Rejection.js
@@ -1,12 +1,10 @@
-"use strict";
-
-exports.fromError = function(a) {
+export function fromError(a) {
   return a;
-};
+}
 
-exports._toError = function(just, nothing, ref) {
+export function _toError(just, nothing, ref) {
   if (ref instanceof Error) {
     return just(ref);
   }
   return nothing;
-};
+}