diff --git a/.eslintrc.json b/.eslintrc.json
index 84cef4f..1c6afb9 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -1,11 +1,9 @@
 {
   "parserOptions": {
-    "ecmaVersion": 5
+    "ecmaVersion": 6,
+    "sourceType": "module"
   },
   "extends": "eslint:recommended",
-  "env": {
-    "commonjs": true
-  },
   "rules": {
     "strict": [2, "global"],
     "block-scoped-var": 2,
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 43d2897..b6ebf3a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,6 +13,8 @@ jobs:
       - uses: actions/checkout@v2
 
       - uses: purescript-contrib/setup-purescript@main
+        with:
+          purescript: "unstable"
 
       - uses: actions/setup-node@v1
         with:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9e2fbd2..92480b5 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 (#41 by @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index f9e0321..a3e7994 100644
--- a/bower.json
+++ b/bower.json
@@ -16,9 +16,9 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-effect": "^3.0.0",
-    "purescript-either": "^5.0.0",
-    "purescript-maybe": "^5.0.0",
-    "purescript-prelude": "^5.0.0"
+    "purescript-effect": "master",
+    "purescript-either": "master",
+    "purescript-maybe": "master",
+    "purescript-prelude": "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/Effect/Exception.js b/src/Effect/Exception.js
index a5aa8c4..40c0eee 100644
--- a/src/Effect/Exception.js
+++ b/src/Effect/Exception.js
@@ -1,36 +1,34 @@
-"use strict";
-
-exports.showErrorImpl = function (err) {
+export function showErrorImpl(err) {
   return err.stack || err.toString();
-};
+}
 
-exports.error = function (msg) {
+export function error(msg) {
   return new Error(msg);
-};
+}
 
-exports.message = function (e) {
+export function message(e) {
   return e.message;
-};
+}
 
-exports.name = function (e) {
+export function name(e) {
   return e.name || "Error";
-};
+}
 
-exports.stackImpl = function (just) {
+export function stackImpl(just) {
   return function (nothing) {
     return function (e) {
       return e.stack ? just(e.stack) : nothing;
     };
   };
-};
+}
 
-exports.throwException = function (e) {
+export function throwException(e) {
   return function () {
     throw e;
   };
-};
+}
 
-exports.catchException = function (c) {
+export function catchException(c) {
   return function (t) {
     return function () {
       try {
@@ -44,4 +42,4 @@ exports.catchException = function (c) {
       }
     };
   };
-};
+}