diff --git a/src/deserializer-manager.coffee b/src/deserializer-manager.coffee
deleted file mode 100644
index 3c73a0b02..000000000
--- a/src/deserializer-manager.coffee
+++ /dev/null
@@ -1,68 +0,0 @@
-{Disposable} = require 'event-kit'
-
-# Extended: Manages the deserializers used for serialized state
-#
-# An instance of this class is always available as the `atom.deserializers`
-# global.
-#
-# ## Examples
-#
-# ```coffee
-# class MyPackageView extends View
-#   atom.deserializers.add(this)
-#
-#   @deserialize: (state) ->
-#     new MyPackageView(state)
-#
-#   constructor: (@state) ->
-#
-#   serialize: ->
-#     @state
-# ```
-module.exports =
-class DeserializerManager
-  constructor: (@atomEnvironment) ->
-    @deserializers = {}
-
-  # Public: Register the given class(es) as deserializers.
-  #
-  # * `deserializers` One or more deserializers to register. A deserializer can
-  #   be any object with a `.name` property and a `.deserialize()` method. A
-  #   common approach is to register a *constructor* as the deserializer for its
-  #   instances by adding a `.deserialize()` class method. When your method is
-  #   called, it will be passed serialized state as the first argument and the
-  #   {Atom} environment object as the second argument, which is useful if you
-  #   wish to avoid referencing the `atom` global.
-  add: (deserializers...) ->
-    @deserializers[deserializer.name] = deserializer for deserializer in deserializers
-    new Disposable =>
-      delete @deserializers[deserializer.name] for deserializer in deserializers
-      return
-
-  getDeserializerCount: ->
-    Object.keys(@deserializers).length
-
-  # Public: Deserialize the state and params.
-  #
-  # * `state` The state {Object} to deserialize.
-  deserialize: (state) ->
-    return unless state?
-
-    if deserializer = @get(state)
-      stateVersion = state.get?('version') ? state.version
-      return if deserializer.version? and deserializer.version isnt stateVersion
-      deserializer.deserialize(state, @atomEnvironment)
-    else
-      console.warn "No deserializer found for", state
-
-  # Get the deserializer for the state.
-  #
-  # * `state` The state {Object} being deserialized.
-  get: (state) ->
-    return unless state?
-
-    name = state.get?('deserializer') ? state.deserializer
-    @deserializers[name]
-
-  clear: ->
-    @deserializers = {}
diff --git a/src/deserializer-manager.js b/src/deserializer-manager.js
new file mode 100644
index 000000000..f5f2e6429
--- /dev/null
+++ b/src/deserializer-manager.js
@@ -0,0 +1,100 @@
+/** @babel */
+
+import {Disposable} from 'event-kit'
+
+// Extended: Manages the deserializers used for serialized state
+//
+// An instance of this class is always available as the `atom.deserializers`
+// global.
+//
+// ## Examples
+//
+// ```coffee
+// class MyPackageView extends View
+//   atom.deserializers.add(this)
+//
+//   @deserialize: (state) ->
+//     new MyPackageView(state)
+//
+//   constructor: (@state) ->
+//
+//   serialize: ->
+//     @state
+// ```
+export default class DeserializerManager {
+  constructor (atomEnvironment) {
+    this.atomEnvironment = atomEnvironment
+    this.deserializers = {}
+  }
+
+  // Public: Register the given class(es) as deserializers.
+  //
+  // * `deserializers` One or more deserializers to register. A deserializer can
+  //   be any object with a `.name` property and a `.deserialize()` method. A
+  //   common approach is to register a *constructor* as the deserializer for its
+  //   instances by adding a `.deserialize()` class method. When your method is
+  //   called, it will be passed serialized state as the first argument and the
+  //   {Atom} environment object as the second argument, which is useful if you
+  //   wish to avoid referencing the `atom` global.
+  add (...deserializers) {
+    for (let i = 0; i < deserializers.length; i++) {
+      let deserializer = deserializers[i]
+      this.deserializers[deserializer.name] = deserializer
+    }
+
+    return new Disposable(() => {
+      for (let j = 0; j < deserializers.length; j++) {
+        let deserializer = deserializers[j]
+        delete this.deserializers[deserializer.name]
+      }
+    })
+  }
+
+  getDeserializerCount () {
+    return Object.keys(this.deserializers).length
+  }
+
+  // Public: Deserialize the state and params.
+  //
+  // * `state` The state {Object} to deserialize.
+  deserialize (state) {
+    if (state == null) {
+      return
+    }
+
+    const deserializer = this.get(state)
+    if (deserializer) {
+      let stateVersion = (
+        (typeof state.get === 'function') && state.get('version') ||
+        state.version
+      )
+
+      if ((deserializer.version != null) && deserializer.version !== stateVersion) {
+        return
+      }
+      return deserializer.deserialize(state, this.atomEnvironment)
+    } else {
+      return console.warn('No deserializer found for', state)
+    }
+  }
+
+  // Get the deserializer for the state.
+  //
+  // * `state` The state {Object} being deserialized.
+  get (state) {
+    if (state == null) {
+      return
+    }
+
+    let stateDeserializer = (
+      (typeof state.get === 'function') && state.get('deserializer') ||
+      state.deserializer
+    )
+
+    return this.deserializers[stateDeserializer]
+  }
+
+  clear () {
+    this.deserializers = {}
+  }
+}