diff --git a/src/comments.js b/src/comments.js
index 7965d0a6..1f3772e1 100644
--- a/src/comments.js
+++ b/src/comments.js
@@ -1,10 +1,6 @@
 "use strict";
 
 const assert = require("assert");
-const types = require("./ast-types");
-const n = types.namedTypes;
-const isArray = types.builtInTypes.array;
-const isObject = types.builtInTypes.object;
 const docBuilders = require("./doc-builders");
 const concat = docBuilders.concat;
 const hardline = docBuilders.hardline;
@@ -19,8 +15,6 @@ const locEnd = util.locEnd;
 const getNextNonSpaceNonCommentCharacter =
   util.getNextNonSpaceNonCommentCharacter;
 
-// TODO Move a non-caching implementation of this function into ast-types,
-// and implement a caching wrapper function here.
 function getSortedChildNodes(node, text, resultArray) {
   if (!node) {
     return;
@@ -28,7 +22,12 @@ function getSortedChildNodes(node, text, resultArray) {
 
   if (resultArray) {
     if (
-      n.Node.check(node) &&
+      node &&
+      node.type &&
+      node.type !== "CommentBlock" &&
+      node.type !== "CommentLine" &&
+      node.type !== "Line" &&
+      node.type !== "Block" &&
       node.type !== "EmptyStatement" &&
       node.type !== "TemplateElement"
     ) {
@@ -52,10 +51,11 @@ function getSortedChildNodes(node, text, resultArray) {
   }
 
   let names;
-  if (isArray.check(node)) {
-    names = Object.keys(node);
-  } else if (isObject.check(node)) {
-    names = types.getFieldNames(node);
+  if (node && typeof node === "object") {
+    names = Object.keys(node).filter(
+      n =>
+        n !== "enclosingNode" && n !== "precedingNode" && n !== "followingNode"
+    );
   } else {
     return;
   }
@@ -153,7 +153,7 @@ function decorateComment(node, comment, text) {
 }
 
 function attach(comments, ast, text) {
-  if (!isArray.check(comments)) {
+  if (!Array.isArray(comments)) {
     return;
   }
 
@@ -928,8 +928,7 @@ function printComments(path, print, options, needsSemi) {
   const value = path.getValue();
   const parent = path.getParentNode();
   const printed = print(path);
-  const comments =
-    n.Node.check(value) && types.getFieldValue(value, "comments");
+  const comments = value && value.comments;
 
   if (!comments || comments.length === 0) {
     return printed;
@@ -940,8 +939,8 @@ function printComments(path, print, options, needsSemi) {
 
   path.each(commentPath => {
     const comment = commentPath.getValue();
-    const leading = types.getFieldValue(comment, "leading");
-    const trailing = types.getFieldValue(comment, "trailing");
+    const leading = comment.leading;
+    const trailing = comment.trailing;
 
     if (leading) {
       const contents = printLeadingComment(commentPath, print, options);
diff --git a/src/parser.js b/src/parser.js
index 8c976446..bee78939 100644
--- a/src/parser.js
+++ b/src/parser.js
@@ -81,8 +81,9 @@ function parseWithBabylon(text) {
     ]
   };
 
+  let ast;
   try {
-    return babylon.parse(text, babylonOptions);
+    ast = babylon.parse(text, babylonOptions);
   } catch (originalError) {
     try {
       return babylon.parse(
@@ -93,21 +94,27 @@ function parseWithBabylon(text) {
       throw originalError;
     }
   }
+  delete ast.tokens;
+  return ast;
 }
 
 function parseWithTypeScript(text) {
   const jsx = isProbablyJsx(text);
+  let ast;
   try {
     try {
       // Try passing with our best guess first.
-      return tryParseTypeScript(text, jsx);
+      ast = tryParseTypeScript(text, jsx);
     } catch (e) {
       // But if we get it wrong, try the opposite.
-      return tryParseTypeScript(text, !jsx);
+      ast = tryParseTypeScript(text, !jsx);
     }
   } catch (e) {
     throw createError(e.message, e.lineNumber, e.column);
   }
+
+  delete ast.tokens;
+  return ast;
 }
 
 function tryParseTypeScript(text, jsx) {
diff --git a/tests/typescript/conformance/internalModules/importDeclarations/__snapshots__/jsfmt.spec.js.snap b/tests/typescript/conformance/internalModules/importDeclarations/__snapshots__/jsfmt.spec.js.snap
index 4e735cf1..bf94b090 100644
--- a/tests/typescript/conformance/internalModules/importDeclarations/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript/conformance/internalModules/importDeclarations/__snapshots__/jsfmt.spec.js.snap
@@ -146,8 +146,7 @@ namespace X {
 }
 
 namespace Z {
-
-// 'y' should be a fundule here
+  // 'y' should be a fundule here
   export import y = X.Y;
 }
 
diff --git a/tests/typescript/webhost/__snapshots__/jsfmt.spec.js.snap b/tests/typescript/webhost/__snapshots__/jsfmt.spec.js.snap
index 04f684ec..eddba86c 100644
--- a/tests/typescript/webhost/__snapshots__/jsfmt.spec.js.snap
+++ b/tests/typescript/webhost/__snapshots__/jsfmt.spec.js.snap
@@ -108,18 +108,14 @@ namespace TypeScript.WebTsc {
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 /// <reference path='..\\..\\src\\compiler\\tsc.ts'/>
 
-namespace TypeScript /*text*/.WebTsc {
-// Load file and read the first two bytes into a string with no interpretation
-// Position must be at 0 before encoding can be changed
-// [0xFF,0xFE] and [0xFE,0xFF] mean utf-16 (little or big endian), otherwise default to utf-8
-// ReadText method always strips byte order mark from resulting string
+namespace TypeScript.WebTsc {
   declare var RealActiveXObject: { new (s: string): any };
 
   function getWScriptSystem() {
     const fso = new RealActiveXObject("Scripting.FileSystemObject");
 
     const fileStream = new ActiveXObject("ADODB.Stream");
-    fileStream.Type = 2;
+    fileStream.Type = 2 /*text*/;
 
     const args: string[] = [];
     for (let i = 0; i < WScript.Arguments.length; i++) {
@@ -144,16 +140,20 @@ namespace TypeScript /*text*/.WebTsc {
             fileStream.Charset = encoding;
             fileStream.LoadFromFile(fileName);
           } else {
+            // Load file and read the first two bytes into a string with no interpretation
             fileStream.Charset = "x-ansi";
             fileStream.LoadFromFile(fileName);
             const bom = fileStream.ReadText(2) || "";
+            // Position must be at 0 before encoding can be changed
             fileStream.Position = 0;
+            // [0xFF,0xFE] and [0xFE,0xFF] mean utf-16 (little or big endian), otherwise default to utf-8
             fileStream.Charset = bom.length >= 2 &&
               ((bom.charCodeAt(0) === 0xff && bom.charCodeAt(1) === 0xfe) ||
                 (bom.charCodeAt(0) === 0xfe && bom.charCodeAt(1) === 0xff))
               ? "unicode"
               : "utf-8";
           }
+          // ReadText method always strips byte order mark from resulting string
           return fileStream.ReadText();
         } catch (e) {
           throw e;