diff --git a/.eslintrc.json b/.eslintrc.json
index 39963d3..81104c4 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 bf067cc..eeae3fb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@ Notable changes to this project are documented in this file. The format is based
 ## [Unreleased]
 
 Breaking changes:
+- Migrate FFI to ES modules (#81 by @kl0tl and @JordanMartinez)
+- Replaced polymorphic proxies with monomorphic `Proxy` (#81 by @JordanMartinez)
 
 New features:
 
diff --git a/bower.json b/bower.json
index 4f90f39..28a4814 100644
--- a/bower.json
+++ b/bower.json
@@ -17,11 +17,11 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-functions": "^5.0.0",
-    "purescript-prelude": "^5.0.0",
-    "purescript-unsafe-coerce": "^5.0.0"
+    "purescript-functions": "master",
+    "purescript-prelude": "master",
+    "purescript-unsafe-coerce": "master"
   },
   "devDependencies": {
-    "purescript-assert": "^5.0.0"
+    "purescript-assert": "master"
   }
 }
diff --git a/package.json b/package.json
index 3ed6897..8382d60 100644
--- a/package.json
+++ b/package.json
@@ -7,8 +7,8 @@
   },
   "devDependencies": {
     "eslint": "^7.15.0",
-    "purescript-psa": "^0.8.0",
-    "pulp": "^15.0.0",
+    "purescript-psa": "^0.8.2",
+    "pulp": "16.0.0-0",
     "rimraf": "^3.0.2"
   }
 }
diff --git a/src/Record.purs b/src/Record.purs
index 3b2c583..11154ca 100644
--- a/src/Record.purs
+++ b/src/Record.purs
@@ -34,10 +34,10 @@ import Unsafe.Coerce (unsafeCoerce)
 -- | get (Proxy :: Proxy "x") :: forall r a. { x :: a | r } -> a
 -- | ```
 get
-  :: forall proxy r r' l a
+  :: forall r r' l a
    . IsSymbol l
   => Cons l a r' r
-  => proxy l
+  => Proxy l
   -> Record r
   -> a
 get l r = unsafeGet (reflectSymbol l) r
@@ -52,11 +52,11 @@ get l r = unsafeGet (reflectSymbol l) r
 -- |   :: forall r a b. a -> { x :: b | r } -> { x :: a | r }
 -- | ```
 set
-  :: forall proxy r1 r2 r l a b
+  :: forall r1 r2 r l a b
    . IsSymbol l
   => Cons l a r r1
   => Cons l b r r2
-  => proxy l
+  => Proxy l
   -> b
   -> Record r1
   -> Record r2
@@ -72,11 +72,11 @@ set l b r = unsafeSet (reflectSymbol l) b r
 -- |   :: forall r a b. (a -> b) -> { x :: a | r } -> { x :: b | r }
 -- | ```
 modify
-  :: forall proxy r1 r2 r l a b
+  :: forall r1 r2 r l a b
    . IsSymbol l
   => Cons l a r r1
   => Cons l b r r2
-  => proxy l
+  => Proxy l
   -> (a -> b)
   -> Record r1
   -> Record r2
@@ -92,11 +92,11 @@ modify l f r = set l (f (get l r)) r
 -- |   :: forall r a. Lacks "x" r => a -> { | r } -> { x :: a | r }
 -- | ```
 insert
-  :: forall proxy r1 r2 l a
+  :: forall r1 r2 l a
    . IsSymbol l
   => Lacks l r1
   => Cons l a r1 r2
-  => proxy l
+  => Proxy l
   -> a
   -> Record r1
   -> Record r2
@@ -115,11 +115,11 @@ insert l a r = unsafeSet (reflectSymbol l) a r
 -- |   :: forall r a. Lacks "x" r => { x :: a | r } -> { | r }
 -- | ```
 delete
-  :: forall proxy r1 r2 l a
+  :: forall r1 r2 l a
    . IsSymbol l
   => Lacks l r1
   => Cons l a r1 r2
-  => proxy l
+  => Proxy l
   -> Record r2
   -> Record r1
 delete l r = unsafeDelete (reflectSymbol l) r
@@ -136,15 +136,15 @@ delete l r = unsafeDelete (reflectSymbol l) r
 -- | rename (Proxy :: Proxy "x") (Proxy :: Proxy "y")
 -- |   :: forall a r. Lacks "x" r => Lacks "y" r => { x :: a | r} -> { y :: a | r}
 -- | ```
-rename :: forall proxy prev next ty input inter output
+rename :: forall prev next ty input inter output
    . IsSymbol prev
   => IsSymbol next
   => Cons prev ty inter input
   => Lacks prev inter
   => Cons next ty inter output
   => Lacks next inter
-  => proxy prev
-  -> proxy next
+  => Proxy prev
+  -> Proxy next
   -> Record input
   -> Record output
 rename prev next record =
@@ -224,7 +224,7 @@ equal
 equal a b = equalFields (Proxy :: Proxy rs) a b
 
 class EqualFields (rs :: RowList Type) (row :: Row Type) | rs -> row where
-  equalFields :: forall rlproxy. rlproxy rs -> Record row -> Record row -> Boolean
+  equalFields :: Proxy rs -> Record row -> Record row -> Boolean
 
 instance equalFieldsCons
   ::
diff --git a/src/Record/Builder.js b/src/Record/Builder.js
index 89df61c..bae6e96 100644
--- a/src/Record/Builder.js
+++ b/src/Record/Builder.js
@@ -1,6 +1,4 @@
-"use strict";
-
-exports.copyRecord = function(rec) {
+export function copyRecord(rec) {
   var copy = {};
   for (var key in rec) {
     if ({}.hasOwnProperty.call(rec, key)) {
@@ -8,34 +6,34 @@ exports.copyRecord = function(rec) {
     }
   }
   return copy;
-};
+}
 
-exports.unsafeInsert = function(l) {
+export function unsafeInsert(l) {
   return function(a) {
     return function(rec) {
       rec[l] = a;
       return rec;
     };
   };
-};
+}
 
-exports.unsafeModify = function(l) {
+export function unsafeModify(l) {
   return function (f) {
     return function(rec) {
       rec[l] = f(rec[l]);
       return rec;
     };
   };
-};
+}
 
-exports.unsafeDelete = function(l) {
+export function unsafeDelete(l) {
   return function(rec) {
     delete rec[l];
     return rec;
   };
-};
+}
 
-exports.unsafeRename = function(l1) {
+export function unsafeRename(l1) {
   return function (l2) {
     return function (rec) {
       rec[l2] = rec[l1];
@@ -43,4 +41,4 @@ exports.unsafeRename = function(l1) {
       return rec;
     };
   };
-};
+}
diff --git a/src/Record/Builder.purs b/src/Record/Builder.purs
index a3bea60..acc204f 100644
--- a/src/Record/Builder.purs
+++ b/src/Record/Builder.purs
@@ -20,6 +20,7 @@ import Data.Function.Uncurried (runFn2)
 import Data.Symbol (class IsSymbol, reflectSymbol)
 import Prim.Row as Row
 import Record.Unsafe.Union (unsafeUnionFn)
+import Type.Proxy (Proxy)
 import Unsafe.Coerce (unsafeCoerce)
 
 foreign import copyRecord :: forall r1. Record r1 -> Record r1
@@ -61,46 +62,46 @@ derive newtype instance categoryBuilder :: Category Builder
 
 -- | Build by inserting a new field.
 insert
-  :: forall proxy l a r1 r2
+  :: forall l a r1 r2
    . Row.Cons l a r1 r2
   => Row.Lacks l r1
   => IsSymbol l
-  => proxy l
+  => Proxy l
   -> a
   -> Builder (Record r1) (Record r2)
 insert l a = Builder \r1 -> unsafeInsert (reflectSymbol l) a r1
 
 -- | Build by modifying an existing field.
 modify
-  :: forall proxy l a b r r1 r2
+  :: forall l a b r r1 r2
    . Row.Cons l a r r1
   => Row.Cons l b r r2
   => IsSymbol l
-  => proxy l
+  => Proxy l
   -> (a -> b)
   -> Builder (Record r1) (Record r2)
 modify l f = Builder \r1 -> unsafeModify (reflectSymbol l) f r1
 
 -- | Build by deleting an existing field.
 delete
-  :: forall proxy l a r1 r2
+  :: forall l a r1 r2
    . IsSymbol l
    => Row.Lacks l r1
    => Row.Cons l a r1 r2
-   => proxy l
+   => Proxy l
    -> Builder (Record r2) (Record r1)
 delete l = Builder \r2 -> unsafeDelete (reflectSymbol l) r2
 
 -- | Build by renaming an existing field.
-rename :: forall proxy l1 l2 a r1 r2 r3
+rename :: forall l1 l2 a r1 r2 r3
    . IsSymbol l1
   => IsSymbol l2
   => Row.Cons l1 a r2 r1
   => Row.Lacks l1 r2
   => Row.Cons l2 a r2 r3
   => Row.Lacks l2 r2
-  => proxy l1
-  -> proxy l2
+  => Proxy l1
+  -> Proxy l2
   -> Builder (Record r1) (Record r3)
 rename l1 l2 = Builder \r1 -> unsafeRename (reflectSymbol l1) (reflectSymbol l2) r1
 
diff --git a/src/Record/Unsafe/Union.js b/src/Record/Unsafe/Union.js
index 637d503..01efccf 100644
--- a/src/Record/Unsafe/Union.js
+++ b/src/Record/Unsafe/Union.js
@@ -1,6 +1,4 @@
-"use strict";
-
-exports.unsafeUnionFn = function(r1, r2) {
+export function unsafeUnionFn(r1, r2) {
   var copy = {};
   for (var k1 in r2) {
     if ({}.hasOwnProperty.call(r2, k1)) {
@@ -13,4 +11,4 @@ exports.unsafeUnionFn = function(r1, r2) {
     }
   }
   return copy;
-};
+}