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 bed7b6f..f5ce863 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 (#36 by @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index ab283dc..7a03fb7 100644
--- a/bower.json
+++ b/bower.json
@@ -16,14 +16,14 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-datetime": "^5.0.0",
-    "purescript-effect": "^3.0.0",
-    "purescript-foreign": "^6.0.0",
-    "purescript-integers": "^5.0.0"
+    "purescript-datetime": "master",
+    "purescript-effect": "master",
+    "purescript-foreign": "master",
+    "purescript-integers": "master"
   },
   "devDependencies": {
-    "purescript-assert": "^5.0.0",
-    "purescript-console": "^5.0.0",
-    "purescript-numbers": "^8.0.0"
+    "purescript-assert": "master",
+    "purescript-console": "master",
+    "purescript-numbers": "master"
   }
 }
diff --git a/packages.dhall b/packages.dhall
index 7a6905b..582d6d3 100644
--- a/packages.dhall
+++ b/packages.dhall
@@ -1,4 +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
diff --git a/spago.dhall b/spago.dhall
index 38704ab..6210f3a 100644
--- a/spago.dhall
+++ b/spago.dhall
@@ -13,7 +13,6 @@
   , "numbers"
   , "partial"
   , "prelude"
-  , "psci-support"
   , "transformers"
   ]
 , packages = ./packages.dhall
diff --git a/src/Data/JSDate.js b/src/Data/JSDate.js
index 4e9bdb3..8db78c4 100644
--- a/src/Data/JSDate.js
+++ b/src/Data/JSDate.js
@@ -1,6 +1,4 @@
 // global exports
-"use strict";
-
 var createDate = function(y, m, d, h, mi, s, ms) {
   var date = new Date(Date.UTC(y, m, d, h, mi, s, ms));
   if (y >= 0 && y < 100) {
@@ -17,28 +15,28 @@ var createLocalDate = function(y, m, d, h, mi, s, ms) {
   return date;
 };
 
-exports.now = function() {
+export function now() {
   return new Date();
-};
+}
 
-exports.isValid = function(date) {
+export function isValid(date) {
   return !isNaN(date.getTime());
-};
+}
 
-exports.toInstantImpl = function(just) {
+export function toInstantImpl(just) {
   return function(nothing) {
     return function(date) {
       var t = date.getTime();
       return isNaN(t) ? nothing : just(t);
     };
   };
-};
+}
 
-exports.fromInstant = function(instant) {
+export function fromInstant(instant) {
   return new Date(instant);
-};
+}
 
-exports.jsdate = function(parts) {
+export function jsdate(parts) {
   return createDate(
     parts.year,
     parts.month,
@@ -48,9 +46,9 @@ exports.jsdate = function(parts) {
     parts.second,
     parts.millisecond
   );
-};
+}
 
-exports.jsdateLocal = function(parts) {
+export function jsdateLocal(parts) {
   return function() {
     return createLocalDate(
       parts.year,
@@ -62,24 +60,24 @@ exports.jsdateLocal = function(parts) {
       parts.millisecond
     );
   };
-};
+}
 
-exports.dateMethod = function(method, date) {
+export function dateMethod(method, date) {
   return date[method]();
-};
+}
 
-exports.dateMethodEff = function(method, date) {
+export function dateMethodEff(method, date) {
   return function() {
     return date[method]();
   };
-};
+}
 
-exports.parse = function(dateString) {
+export function parse(dateString) {
   return function() {
     return new Date(dateString);
   };
-};
+}
 
-exports.fromTime = function(time) {
+export function fromTime(time) {
   return new Date(time);
-};
+}
diff --git a/test/Test/Main.js b/test/Test/Main.js
index fc80ce6..0892f2c 100644
--- a/test/Test/Main.js
+++ b/test/Test/Main.js
@@ -1,3 +1 @@
-"use strict";
-
-exports.myDate = new Date();
+export const myDate = new Date();