diff --git a/src/collection.js b/src/collection.js
deleted file mode 100644
index e73d2fa76..000000000
--- a/src/collection.js
+++ /dev/null
@@ -1,48 +0,0 @@
-'use strict'
-import BlankNode from './blank-node'
-import ClassOrder from './class-order'
-import Node from './node-internal'
-
-export default class Collection extends Node {
-  constructor (initial) {
-    super()
-    this.termType = Collection.termType
-    this.id = BlankNode.nextId++
-    this.elements = []
-    this.closed = false
-    if (initial && initial.length > 0) {
-      initial.forEach(element => {
-        this.elements.push(Node.fromValue(element))
-      })
-    }
-  }
-  append (element) {
-    return this.elements.push(element)
-  }
-  close () {
-    this.closed = true
-    return this.closed
-  }
-  shift () {
-    return this.elements.shift()
-  }
-  substitute (bindings) {
-    var elementsCopy = this.elements.map(function (ea) {
-      ea.substitute(bindings)
-    })
-    return new Collection(elementsCopy)
-  }
-  toNT () {
-    return BlankNode.NTAnonymousNodePrefix + this.id
-  }
-  toString () {
-    return '(' + this.elements.join(' ') + ')'
-  }
-  unshift (element) {
-    return this.elements.unshift(element)
-  }
-}
-Collection.termType = 'Collection'
-Collection.prototype.classOrder = ClassOrder['Collection']
-Collection.prototype.compareTerm = BlankNode.prototype.compareTerm
-Collection.prototype.isVar = 0
diff --git a/src/collection.ts b/src/collection.ts
new file mode 100644
index 000000000..2b9627e1c
--- /dev/null
+++ b/src/collection.ts
@@ -0,0 +1,90 @@
+import BlankNode from './blank-node'
+import ClassOrder from './class-order'
+import Node from './node-internal'
+import { ValueType, Bindings } from './types';
+
+/**
+* A collection of other RDF nodes
+*/
+export default class Collection extends Node {
+  /**
+   * The identifier for this collection
+   */
+  id: number;
+  /**
+   * The nodes in this collection
+   */
+  elements: Node[];
+  /**
+   * Whether this collection is closed
+   */
+  closed: boolean;
+  /**
+   * Initializes this collection
+   * @param initial The initial elements
+   */
+  constructor(initial: ReadonlyArray<ValueType>) {
+    super()
+    this.termType = Collection.termType
+    this.id = BlankNode.nextId++
+    this.elements = []
+    this.closed = false
+    if (initial && initial.length > 0) {
+      initial.forEach(element => {
+        this.elements.push(Node.fromValue(element))
+      })
+    }
+  }
+  /**
+   * Appends an element to this collection
+   * @param element The new element
+   */
+  append (element: Node): number {
+    return this.elements.push(element)
+  }
+  /**
+   * Closes this collection
+   */
+  close (): boolean {
+    this.closed = true
+    return this.closed
+  }
+  /**
+   * Removes the first element from the collection (and return it)
+   */
+  shift (): Node | undefined {
+    return this.elements.shift()
+  }
+  /**
+   * Gets a new Collection with the substituting bindings applied
+   * @param bindings The bindings to substitute
+   */
+  substitute(bindings: Bindings): Collection {
+    var elementsCopy = this.elements.map(function (ea) {
+      ea.substitute(bindings)
+    })
+    return new Collection(elementsCopy as [])
+  }
+  toNT () {
+    return BlankNode.NTAnonymousNodePrefix + this.id
+  }
+  /**
+   * Serializes the collection to a string.
+   * Surounded by (parantheses) and seperated by spaces.
+   */
+  toString () {
+    return '(' + this.elements.join(' ') + ')'
+  }
+  /**
+   * Preprends the specified element to the colelction's front
+   * @param element The element to preprend
+   */
+  unshift (element: Node): number {
+    return this.elements.unshift(element)
+  }
+  static termType: string;
+}
+Collection.termType = 'Collection'
+Collection.prototype.classOrder = ClassOrder['Collection']
+Collection.prototype.compareTerm = BlankNode.prototype.compareTerm
+Collection.prototype.isVar = false