diff --git a/.gitignore b/.gitignore
index 7050558..332b6cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,3 +5,4 @@
 /bower_components/
 /node_modules/
 /output/
+package-lock.json
diff --git a/LICENSE b/LICENSE
index 58b0299..311379c 100644
--- a/LICENSE
+++ b/LICENSE
@@ -1,20 +1,26 @@
-The MIT License (MIT)
+Copyright 2018 PureScript
 
-Copyright (c) 2014 PureScript
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
 
-Permission is hereby granted, free of charge, to any person obtaining a copy of
-this software and associated documentation files (the "Software"), to deal in
-the Software without restriction, including without limitation the rights to
-use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
-the Software, and to permit persons to whom the Software is furnished to do so,
-subject to the following conditions:
+1. Redistributions of source code must retain the above copyright notice, this
+list of conditions and the following disclaimer.
 
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
+2. Redistributions in binary form must reproduce the above copyright notice,
+this list of conditions and the following disclaimer in the documentation and/or
+other materials provided with the distribution.
 
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
-COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
-IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
-CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+3. Neither the name of the copyright holder nor the names of its contributors
+may be used to endorse or promote products derived from this software without
+specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/bower.json b/bower.json
index a4b8090..f50e6e4 100644
--- a/bower.json
+++ b/bower.json
@@ -1,8 +1,7 @@
 {
   "name": "purescript-refs",
   "homepage": "https://github.com/purescript/purescript-refs",
-  "description": "Mutable value references",
-  "license": "MIT",
+  "license": "BSD-3-Clause",
   "repository": {
     "type": "git",
     "url": "git://github.com/purescript/purescript-refs.git"
@@ -17,6 +16,7 @@
     "package.json"
   ],
   "dependencies": {
-    "purescript-eff": "^3.0.0"
+    "purescript-effect": "^2.0.0",
+    "purescript-prelude": "^4.0.0"
   }
 }
diff --git a/package.json b/package.json
index 26d81a7..02e36ea 100644
--- a/package.json
+++ b/package.json
@@ -5,9 +5,9 @@
     "build": "eslint src && pulp build -- --censor-lib --strict"
   },
   "devDependencies": {
-    "eslint": "^3.17.1",
-    "pulp": "^10.0.4",
-    "purescript-psa": "^0.5.0-rc.1",
-    "rimraf": "^2.6.1"
+    "eslint": "^4.19.1",
+    "pulp": "^12.2.0",
+    "purescript-psa": "^0.6.0",
+    "rimraf": "^2.6.2"
   }
 }
diff --git a/src/Control/Monad/Eff/Ref.purs b/src/Control/Monad/Eff/Ref.purs
deleted file mode 100644
index 09a4ae6..0000000
--- a/src/Control/Monad/Eff/Ref.purs
+++ /dev/null
@@ -1,35 +0,0 @@
--- | This module defines an effect and actions for working with
--- | global mutable variables.
--- |
--- | _Note_: The `Control.Monad.ST` provides a _safe_ alternative
--- | to global mutable variables when mutation is restricted to a
--- | local scope.
-module Control.Monad.Eff.Ref where
-
-import Prelude (Unit, unit)
-import Control.Monad.Eff (Eff, kind Effect)
-
--- | The effect associated with the use of global mutable variables.
-foreign import data REF :: Effect
-
--- | A value of type `Ref a` represents a mutable reference
--- | which holds a value of type `a`.
-foreign import data Ref :: Type -> Type
-
--- | Create a new mutable reference containing the specified value.
-foreign import newRef :: forall s r. s -> Eff (ref :: REF | r) (Ref s)
-
--- | Read the current value of a mutable reference
-foreign import readRef :: forall s r. Ref s -> Eff (ref :: REF | r) s
-
--- | Update the value of a mutable reference by applying a function
--- | to the current value.
-foreign import modifyRef' :: forall s b r. Ref s -> (s -> { state :: s, value :: b }) -> Eff (ref :: REF | r) b
-
--- | Update the value of a mutable reference by applying a function
--- | to the current value.
-modifyRef :: forall s r. Ref s -> (s -> s) -> Eff (ref :: REF | r) Unit
-modifyRef ref f = modifyRef' ref (\s -> { state: f s, value: unit })
-
--- | Update the value of a mutable reference to the specified value.
-foreign import writeRef :: forall s r. Ref s -> s -> Eff (ref :: REF | r) Unit
diff --git a/src/Control/Monad/Eff/Ref/Unsafe.purs b/src/Control/Monad/Eff/Ref/Unsafe.purs
deleted file mode 100644
index fec0c3d..0000000
--- a/src/Control/Monad/Eff/Ref/Unsafe.purs
+++ /dev/null
@@ -1,16 +0,0 @@
--- | Unsafe functions for working with mutable references.
-
-module Control.Monad.Eff.Ref.Unsafe where
-
-import Control.Monad.Eff (Eff)
-import Control.Monad.Eff.Ref (REF)
-import Control.Monad.Eff.Unsafe (unsafeCoerceEff)
-
--- | This handler function unsafely removes the `Ref` effect from an
--- | effectful action.
--- |
--- | This function might be used when it is impossible to prove to the
--- | typechecker that a particular mutable reference does not escape
--- | its scope.
-unsafeRunRef :: forall eff a. Eff (ref :: REF | eff) a -> Eff eff a
-unsafeRunRef = unsafeCoerceEff
diff --git a/src/Control/Monad/Eff/Ref.js b/src/Effect/Ref.js
similarity index 62%
rename from src/Control/Monad/Eff/Ref.js
rename to src/Effect/Ref.js
index f42e7e5..4bcefd0 100644
--- a/src/Control/Monad/Eff/Ref.js
+++ b/src/Effect/Ref.js
@@ -1,19 +1,19 @@
 "use strict";
 
-exports.newRef = function (val) {
+exports.new = function (val) {
   return function () {
     return { value: val };
   };
 };
 
-exports.readRef = function (ref) {
+exports.read = function (ref) {
   return function () {
     return ref.value;
   };
 };
 
-exports["modifyRef'"] = function (ref) {
-  return function (f) {
+exports["modify'"] = function (f) {
+  return function (ref) {
     return function () {
       var t = f(ref.value);
       ref.value = t.state;
@@ -22,8 +22,8 @@ exports["modifyRef'"] = function (ref) {
   };
 };
 
-exports.writeRef = function (ref) {
-  return function (val) {
+exports.write = function (val) {
+  return function (ref) {
     return function () {
       ref.value = val;
       return {};
diff --git a/src/Effect/Ref.purs b/src/Effect/Ref.purs
new file mode 100644
index 0000000..edc1f8e
--- /dev/null
+++ b/src/Effect/Ref.purs
@@ -0,0 +1,33 @@
+-- | This module defines an effect and actions for working with
+-- | global mutable variables.
+-- |
+-- | _Note_: `Control.Monad.ST` provides a _safe_ alternative
+-- | to global mutable variables when mutation is restricted to a
+-- | local scope.
+module Effect.Ref where
+
+import Prelude
+
+import Effect (Effect)
+
+-- | A value of type `Ref a` represents a mutable reference
+-- | which holds a value of type `a`.
+foreign import data Ref :: Type -> Type
+
+-- | Create a new mutable reference containing the specified value.
+foreign import new :: forall s. s -> Effect (Ref s)
+
+-- | Read the current value of a mutable reference
+foreign import read :: forall s. Ref s -> Effect s
+
+-- | Update the value of a mutable reference by applying a function
+-- | to the current value.
+foreign import modify' :: forall s b. (s -> { state :: s, value :: b }) -> Ref s -> Effect b
+
+-- | Update the value of a mutable reference by applying a function
+-- | to the current value. The updated value is returned.
+modify :: forall s. (s -> s) -> Ref s -> Effect s
+modify f = modify' \s -> let s' = f s in { state: s', value: s' }
+
+-- | Update the value of a mutable reference to the specified value.
+foreign import write :: forall s. s -> Ref s -> Effect Unit