diff --git a/lib/6to5/generators/expressions.js b/lib/6to5/generators/expressions.js
index e8909f6643..6e17fa83fa 100644
--- a/lib/6to5/generators/expressions.js
+++ b/lib/6to5/generators/expressions.js
@@ -1,10 +1,11 @@
+var t = require("../types");
 var _ = require("lodash");
 
 exports.UnaryExpression = function (node, print) {
   this.push(node.operator);
 
   var arg = node.argument;
-  if (/[a-z]$/.test(node.operator) || arg.type === "UpdateExpression" || arg.type === "UnaryExpression") {
+  if (/[a-z]$/.test(node.operator) || t.isUpdateExpression(arg) || t.isUnaryExpression(arg)) {
     this.push(" ");
   }
 
diff --git a/lib/6to5/generators/jsx.js b/lib/6to5/generators/jsx.js
index fb0aadf93f..3544da04ac 100644
--- a/lib/6to5/generators/jsx.js
+++ b/lib/6to5/generators/jsx.js
@@ -1,3 +1,4 @@
+var t = require("../types");
 var _ = require("lodash");
 
 exports.XJSAttribute = function (node, print) {
@@ -45,7 +46,7 @@ exports.XJSElement = function (node, print) {
 
   this.indent();
   _.each(node.children, function (child) {
-    if (child.type === "Literal" && typeof child.value === "string") {
+    if (t.isLiteral(child) && typeof child.value === "string") {
       if (/\S/.test(child.value)) {
         return self.push(child.value.replace(/^\s+|\s+$/g, ""));
       } else if (/\n/.test(child.value)) {
diff --git a/lib/6to5/generators/methods.js b/lib/6to5/generators/methods.js
index b387ded065..e35d329622 100644
--- a/lib/6to5/generators/methods.js
+++ b/lib/6to5/generators/methods.js
@@ -1,3 +1,5 @@
+var t = require("../types");
+
 exports._params = function (node, print) {
   var self = this;
 
@@ -79,7 +81,7 @@ exports.FunctionExpression = function (node, print) {
 };
 
 exports.ArrowFunctionExpression = function (node, print) {
-  if (node.params.length === 1 && !node.defaults.length && !node.rest && node.params[0].type === "Identifier") {
+  if (node.params.length === 1 && !node.defaults.length && !node.rest && t.isIdentifier(node.params[0])) {
     print(node.params[0]);
   } else {
     this._params(node, print);
diff --git a/lib/6to5/generators/modules.js b/lib/6to5/generators/modules.js
index 1f6cecce9d..ed6c068b70 100644
--- a/lib/6to5/generators/modules.js
+++ b/lib/6to5/generators/modules.js
@@ -1,3 +1,4 @@
+var t = require("../types");
 var _ = require("lodash");
 
 exports.ImportSpecifier =
@@ -21,7 +22,7 @@ exports.ExportDeclaration = function (node, print) {
   if (node.default) {
     this.push(" default");
   } else if (specifiers && specifiers.length > 0) {
-    if (specifiers.length === 1 && specifiers[0].type === "ExportBatchSpecifier") {
+    if (specifiers.length === 1 && t.isExportBatchSpecifier(specifiers[0])) {
       this.push(" *");
     } else {
       this.push(" { ");
diff --git a/lib/6to5/modules/amd.js b/lib/6to5/modules/amd.js
index 5cc573f7ca..65e23f157c 100644
--- a/lib/6to5/modules/amd.js
+++ b/lib/6to5/modules/amd.js
@@ -62,7 +62,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
 
   var ref;
 
-  if (specifier.type === "ImportBatchSpecifier") {
+  if (t.isImportBatchSpecifier(specifier)) {
     // import * as bar from "foo";
     ref = this._push(node);
   } else {
diff --git a/lib/6to5/modules/common.js b/lib/6to5/modules/common.js
index 551968768c..6fe4131d4e 100644
--- a/lib/6to5/modules/common.js
+++ b/lib/6to5/modules/common.js
@@ -53,7 +53,7 @@ CommonJSFormatter.prototype.export = function (node, nodes) {
     }, true));
   } else {
     var id = declar.id;
-    if (declar.type === "VariableDeclaration") {
+    if (t.isVariableDeclaration(declar)) {
       id = declar.declarations[0].id;
     }
 
@@ -64,7 +64,7 @@ CommonJSFormatter.prototype.export = function (node, nodes) {
 
     nodes.push(declar);
 
-    if (declar.type === "FunctionDeclaration") {
+    if (t.isFunctionDeclaration(declar)) {
       assign._blockHoist = true;
     }
 
@@ -76,7 +76,7 @@ CommonJSFormatter.prototype._exportSpecifier = function (getRef, specifier, node
   var variableName = t.getSpecifierName(specifier);
 
   if (node.source) {
-    if (specifier.type === "ExportBatchSpecifier") {
+    if (t.isExportBatchSpecifier(specifier)) {
       // export * from "foo";
       nodes.push(util.template("exports-wildcard", {
         OBJECT: getRef()
diff --git a/lib/6to5/transformers/_alias-functions.js b/lib/6to5/transformers/_alias-functions.js
index d1435f47c2..174e9355c0 100644
--- a/lib/6to5/transformers/_alias-functions.js
+++ b/lib/6to5/transformers/_alias-functions.js
@@ -39,9 +39,9 @@ var go = function (getBody, node, file) {
 
       var getId;
 
-      if (node.type === "Identifier" && node.name === "arguments") {
+      if (t.isIdentifier(node) && node.name === "arguments") {
         getId = getArgumentsId;
-      } else if (node.type === "ThisExpression") {
+      } else if (t.isThisExpression(node)) {
         getId = getThisId;
       } else {
         return;
diff --git a/lib/6to5/transformers/classes.js b/lib/6to5/transformers/classes.js
index 64e1298ebe..1ab7f74326 100644
--- a/lib/6to5/transformers/classes.js
+++ b/lib/6to5/transformers/classes.js
@@ -15,7 +15,7 @@ exports.ClassExpression = function (node, parent, file) {
 };
 
 var getMemberExpressionObject = function (node) {
-  while (node.type === "MemberExpression") {
+  while (t.isMemberExpression(node)) {
     node = node.object;
   }
   return node;
@@ -29,9 +29,9 @@ var buildClass = function (node, file) {
   var superClassCallee   = node.superClass;
 
   if (superName) {
-    if (superName.type === "MemberExpression") {
+    if (t.isMemberExpression(superName)) {
       superClassArgument = superClassCallee = getMemberExpressionObject(superName);
-    } else if (superName.type !== "Identifier") {
+    } else if (t.isIdentifier(superName)) {
       superClassArgument = superName;
       superClassCallee = superName = b.identifier(file.generateUid("ref"));
     }
@@ -138,7 +138,7 @@ var buildClassBody = function (file, construct, body, className, superName, node
 var superIdentifier = function (superName, methodNode, methodName, node, parent) {
   if (parent.property === node) {
     return;
-  } else if (parent.type === "CallExpression" && parent.callee === node) {
+  } else if (t.isCallExpression(parent) && parent.callee === node) {
     // super(); -> ClassName.prototype.MethodName.call(this);
     parent.arguments.unshift(b.thisExpression());
 
@@ -156,7 +156,7 @@ var superIdentifier = function (superName, methodNode, methodName, node, parent)
       node = b.memberExpression(node, b.identifier(methodName));
       return b.memberExpression(node, b.identifier("call"));
     }
-  } else if (parent.type === "MemberExpression" && !methodNode.static) {
+  } else if (t.isMemberExpression(parent) && !methodNode.static) {
     // super.test -> ClassName.prototype.test
     return b.memberExpression(superName, b.identifier("prototype"));
   } else {
@@ -168,11 +168,11 @@ var replaceInstanceSuperReferences = function (superName, method, methodNode, me
   superName = superName || b.identifier("Function");
 
   traverse(method, function (node, parent) {
-    if (node.type === "Identifier" && node.name === "super") {
+    if (t.isIdentifier(node) && node.name === "super") {
       return superIdentifier(superName, methodNode, methodName, node, parent);
-    } else if (node.type === "CallExpression") {
+    } else if (t.isCallExpression(node)) {
       var callee = node.callee;
-      if (callee.type !== "MemberExpression") return;
+      if (!t.isMemberExpression(callee)) return;
       if (callee.object.name !== "super") return;
 
       //  super.test(); -> ClassName.prototype.MethodName.call(this);
diff --git a/lib/6to5/transformers/constants.js b/lib/6to5/transformers/constants.js
index 12af051e38..529d6f69f9 100644
--- a/lib/6to5/transformers/constants.js
+++ b/lib/6to5/transformers/constants.js
@@ -1,5 +1,6 @@
 var traverse = require("../traverse");
 var util     = require("../util");
+var t        = require("../types");
 var _        = require("lodash");
 
 exports.Program =
@@ -16,7 +17,7 @@ exports.ForStatement = function (node, parent, file) {
   };
 
   _.each(node.body, function (child) {
-    if (child && child.type === "VariableDeclaration" && child.kind === "const") {
+    if (child && t.isVariableDeclaration(child) && child.kind === "const") {
       _.each(child.declarations, function (declar) {
         _.each(util.getIds(declar.id), function (name) {
           check(declar, name);
@@ -34,11 +35,9 @@ exports.ForStatement = function (node, parent, file) {
   traverse(node, function (child) {
     if (child._ignoreConstant) return;
 
-    if (child.type === "VariableDeclarator" ||
-        child.type === "FunctionDeclaration" ||
-        child.type === "ClassDeclaration") {
+    if (t.isVariableDeclarator(child) || t.isFunctionDeclaration(child) || t.isClassDeclaration(child)) {
       check(child, child.id.name);
-    } else if (child.type === "AssignmentExpression") {
+    } else if (t.isAssignmentExpression(child)) {
       check(child, child.left.name);
     }
   });
diff --git a/lib/6to5/transformers/destructuring.js b/lib/6to5/transformers/destructuring.js
index b1513dea50..3e987d602f 100644
--- a/lib/6to5/transformers/destructuring.js
+++ b/lib/6to5/transformers/destructuring.js
@@ -13,11 +13,11 @@ var buildVariableAssign = function (kind, id, init) {
 };
 
 var push = function (kind, nodes, elem, parentId) {
-  if (elem.type === "ObjectPattern") {
+  if (t.isObjectPattern(elem)) {
     pushObjectPattern(kind, nodes, elem, parentId);
-  } else if (elem.type === "ArrayPattern") {
+  } else if (t.isArrayPattern(elem)) {
     pushArrayPattern(kind, nodes, elem, parentId);
-  } else if (elem.type === "MemberExpression") {
+  } else if (t.isMemberExpression(elem)) {
     nodes.push(buildVariableAssign(false, elem, parentId));
   } else {
     nodes.push(buildVariableAssign(kind, elem, parentId));
@@ -124,7 +124,7 @@ exports.ExpressionStatement = function (node, parent, file) {
 };
 
 exports.VariableDeclaration = function (node, parent, file) {
-  if (parent.type === "ForInStatement") return;
+  if (t.isForInStatement(parent)) return;
 
   var nodes = [];
 
diff --git a/lib/6to5/transformers/for-of.js b/lib/6to5/transformers/for-of.js
index d051d07dd5..587a06716b 100644
--- a/lib/6to5/transformers/for-of.js
+++ b/lib/6to5/transformers/for-of.js
@@ -9,9 +9,9 @@ exports.ForOfStatement = function (node, parent, file) {
   var stepKey = b.identifier(file.generateUid("step"));
   var stepValueId = b.memberExpression(stepKey, b.identifier("value"));
 
-  if (left.type === "Identifier") {
+  if (t.isIdentifier(left)) {
     declar = b.expressionStatement(b.assignmentExpression("=", left, stepValueId));
-  } else if (left.type === "VariableDeclaration") {
+  } else if (t.isVariableDeclaration(left)) {
     declar = b.variableDeclaration(left.kind, [
       b.variableDeclarator(left.declarations[0].id, stepValueId)
     ]);
diff --git a/lib/6to5/transformers/jsx.js b/lib/6to5/transformers/jsx.js
index b4e881b34e..d4510b03be 100644
--- a/lib/6to5/transformers/jsx.js
+++ b/lib/6to5/transformers/jsx.js
@@ -37,7 +37,7 @@ exports.XJSNamespacedName = function () {
 
 exports.XJSMemberExpression = {
   exit: function (node) {
-    node.computed = node.property.type === "Literal";
+    node.computed = t.isLiteral(node.property);
     node.type = "MemberExpression";
   }
 };
@@ -64,7 +64,7 @@ exports.XJSOpeningElement = {
   exit: function (node, parent, file) {
     var tagExpr = node.name;
 
-    if (tagExpr.type === "Identifier") {
+    if (t.isIdentifier(tagExpr)) {
       var tagName = tagExpr.name;
 
       if (/[a-z]/.exec(tagName[0]) || _.contains(tagName, "-")) {
diff --git a/lib/6to5/transformers/let-scoping.js b/lib/6to5/transformers/let-scoping.js
index 439bde7bcd..157e46abf7 100644
--- a/lib/6to5/transformers/let-scoping.js
+++ b/lib/6to5/transformers/let-scoping.js
@@ -27,7 +27,7 @@ exports.VariableDeclaration = function (node, parent, file) {
     if (t.isReferenced(node, parent)) return id;
   };
 
-  var isProgram = parent.type === "Program";
+  var isProgram = t.isProgram(parent);
 
   var replace = function (node, parent) {
     if (!isProgram && _.contains(t.FUNCTION_TYPES, node.type)) {
@@ -40,7 +40,7 @@ exports.VariableDeclaration = function (node, parent, file) {
       });
 
       if (letReferences.length) {
-        if (node.type === "FunctionDeclaration") {
+        if (t.isFunctionDeclaration(node)) {
           throw new Error("`FunctionDeclaration`s that use `let` and `constant` references aren't allowed outside of the root scope");
         } else {
           var func = b.functionExpression(null, letReferences, b.blockStatement([
diff --git a/lib/6to5/transformers/react.js b/lib/6to5/transformers/react.js
index e527088882..f98b0cc28d 100644
--- a/lib/6to5/transformers/react.js
+++ b/lib/6to5/transformers/react.js
@@ -1,4 +1,5 @@
 var b = require("../builders");
+var t = require("../types");
 var _ = require("lodash");
 
 var addDisplayName = function (id, call) {
@@ -42,22 +43,22 @@ exports.Property =
 exports.VariableDeclarator = function (node) {
   var left, right;
 
-  if (node.type === "AssignmentExpression") {
+  if (t.isAssignmentExpression(node)) {
     left = node.left;
     right = node.right;
-  } else if (node.type === "Property") {
+  } else if (t.isProperty(node)) {
     left = node.key;
     right = node.value;
-  } else if (node.type === "VariableDeclarator") {
+  } else if (t.isVariableDeclarator(node)) {
     left = node.id;
     right = node.init;
   }
 
-  if (left && left.type === "MemberExpression") {
+  if (t.isMemberExpression(left)) {
     left = left.property;
   }
 
-  if (left && left.type === "Identifier") {
+  if (t.isIdentifier(left)) {
     addDisplayName(left.name, right);
   }
 };
diff --git a/lib/6to5/transformers/spread.js b/lib/6to5/transformers/spread.js
index dcb9cee196..01100cb48b 100644
--- a/lib/6to5/transformers/spread.js
+++ b/lib/6to5/transformers/spread.js
@@ -1,5 +1,6 @@
 var util = require("../util");
 var b    = require("../builders");
+var t    = require("../types");
 var _    = require("lodash");
 
 var getSpreadLiteral = function (spread, file) {
@@ -16,7 +17,7 @@ var getSpreadLiteral = function (spread, file) {
 var hasSpread = function (nodes) {
   var has = false;
   _.each(nodes, function (node) {
-    if (node.type === "SpreadElement") {
+    if (t.isSpreadElement(node)) {
       has = true;
       return false;
     }
@@ -36,7 +37,7 @@ var build = function (props, file) {
   };
 
   _.each(props, function (prop) {
-    if (prop.type === "SpreadElement") {
+    if (t.isSpreadElement(prop)) {
       push();
       nodes.push(getSpreadLiteral(prop, file));
     } else {
@@ -80,7 +81,7 @@ exports.CallExpression = function (node, parent, file) {
 
   var callee = node.callee;
 
-  if (callee.type === "MemberExpression") {
+  if (t.isMemberExpression(callee)) {
     contextLiteral = callee.object;
 
     if (callee.computed) {
diff --git a/lib/6to5/transformers/template-literals.js b/lib/6to5/transformers/template-literals.js
index ecfba6057e..869a42ed64 100644
--- a/lib/6to5/transformers/template-literals.js
+++ b/lib/6to5/transformers/template-literals.js
@@ -1,3 +1,4 @@
+var t = require("../types");
 var b = require("../builders");
 var _ = require("lodash");
 
@@ -34,7 +35,7 @@ exports.TemplateLiteral = function (node) {
   if (nodes.length > 1) {
     // remove redundant '' at the end of the expression
     var last = _.last(nodes);
-    if (last.type === "Literal" && last.value === "") nodes.pop();
+    if (t.isLiteral(last) && last.value === "") nodes.pop();
 
     var root = buildBinaryExpression(nodes.shift(), nodes.shift());
 
diff --git a/lib/6to5/types.js b/lib/6to5/types.js
index d8f73a0b22..f42d6d9159 100644
--- a/lib/6to5/types.js
+++ b/lib/6to5/types.js
@@ -196,11 +196,11 @@ t.needsParans = function (node, parent) {
   if (t.isYieldExpression(node)) {
     return t.isBinary(parent)
         || t.isUnaryLike(parent)
-        || parent.type === "CallExpression"
-        || parent.type === "MemberExpression"
-        || parent.type === "NewExpression"
-        || parent.type === "ConditionalExpression"
-        || parent.type === "YieldExpression";
+        || t.isCallExpression(parent)
+        || t.isMemberExpression(parent)
+        || t.isNewExpression(parent)
+        || t.isConditionalExpression(parent)
+        || t.isYieldExpression(parent);
   }
 
   if (t.isNewExpression(parent) && parent.callee === node) {
diff --git a/lib/6to5/util.js b/lib/6to5/util.js
index 6e93d50c41..5e1eb5ebac 100644
--- a/lib/6to5/util.js
+++ b/lib/6to5/util.js
@@ -4,6 +4,7 @@ var acorn      = require("acorn-6to5");
 var path       = require("path");
 var util       = require("util");
 var fs         = require("fs");
+var t          = require("./types");
 var b          = require("./builders");
 var _          = require("lodash");
 
@@ -26,17 +27,15 @@ exports.list = function (val) {
 exports.getUid = function (parent, file) {
   var node;
 
-  if (parent.type === "AssignmentExpression") {
+  if (t.isAssignmentExpression(parent)) {
     node = parent.left;
-  } else if (parent.type === "VariableDeclarator") {
+  } else if (t.isVariableDeclarator(parent)) {
     node = parent.id;
   }
 
   var id = "ref";
 
-  if (node && node.type === "Identifier") {
-    id = node.name;
-  }
+  if (t.isIdentifier(node)) id = node.name;
 
   return b.identifier(file.generateUid(id));
 };
@@ -55,13 +54,13 @@ exports.getIds = function (node) {
   while (search.length) {
     var id = search.shift();
 
-    if (id.type === "Identifier") {
+    if (t.isIdentifier(id)) {
       ids.push(id.name);
-    } else if (id.type === "ArrayPattern") {
+    } else if (t.isArrayPattern(id)) {
       _.each(id.elements, function (elem) {
         search.push(elem);
       });
-    } else if (id.type === "ObjectPattern") {
+    } else if (t.isObjectPattern(id)) {
       _.each(id.properties, function (prop) {
         search.push(prop.value);
       });
@@ -110,7 +109,7 @@ exports.buildDefineProperties = function (mutatorMap) {
 
     _.each(map, function (node, key) {
       node = _.clone(node);
-      if (node.type === "MethodDefinition") node = node.value;
+      if (t.isMethodDefinition(node)) node = node.value;
       mapNode.properties.push(b.property("init", b.identifier(key), node));
     });
 
@@ -128,7 +127,7 @@ exports.template = function (name, nodes, keepExpression) {
 
   if (!_.isEmpty(nodes)) {
     traverse(template, function (node) {
-      if (node.type === "Identifier" && _.has(nodes, node.name)) {
+      if (t.isIdentifier(node) && _.has(nodes, node.name)) {
         var newNode = nodes[node.name];
         if (_.isString(newNode)) {
           node.name = newNode;
@@ -141,7 +140,7 @@ exports.template = function (name, nodes, keepExpression) {
 
   var node = template.body[0];
 
-  if (!keepExpression && node.type === "ExpressionStatement") {
+  if (!keepExpression && t.isExpressionStatement(node)) {
     return node.expression;
   } else {
     return node;