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 8d9a469..b543888 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 (#22 by @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index 6809a78..fcd1462 100644
--- a/bower.json
+++ b/bower.json
@@ -16,13 +16,13 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-console": "^5.0.0",
-    "purescript-effect": "^3.0.0",
-    "purescript-integers": "^5.0.0",
-    "purescript-math": "^3.0.0",
-    "purescript-numbers": "^8.0.0",
-    "purescript-partial": "^3.0.0",
-    "purescript-prelude": "^5.0.0",
-    "purescript-refs": "^5.0.0"
+    "purescript-console": "master",
+    "purescript-effect": "master",
+    "purescript-integers": "master",
+    "purescript-math": "master",
+    "purescript-numbers": "master",
+    "purescript-partial": "master",
+    "purescript-prelude": "master",
+    "purescript-refs": "master"
   }
 }
diff --git a/package.json b/package.json
index d3602c1..c8e10e0 100644
--- a/package.json
+++ b/package.json
@@ -6,8 +6,8 @@
     "test": "pulp test"
   },
   "devDependencies": {
-    "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/Performance/Minibench.js b/src/Performance/Minibench.js
index 26cf479..f5e8314 100644
--- a/src/Performance/Minibench.js
+++ b/src/Performance/Minibench.js
@@ -1,11 +1,9 @@
-"use strict";
+export const hrTime = process.hrtime;
 
-exports.hrTime = process.hrtime;
-
-exports.gc = function() {
+export function gc() {
   global.gc && global.gc();
-};
+}
 
-exports.toFixed = function(n) {
+export function toFixed(n) {
   return n.toFixed(2);
-};
+}