diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index ba4ed2faaf..dce01a04cc 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -389,7 +389,7 @@ File.prototype.checkNode = function (node, scope) {
 
   check(node, scope);
 
-  traverse(node, checkTransformerVisitor, scope, {
+  scope.traverse(node, checkTransformerVisitor, {
     check: check
   });
 };
diff --git a/lib/6to5/transformation/helpers/name-method.js b/lib/6to5/transformation/helpers/name-method.js
index c1876859f9..114122a9c7 100644
--- a/lib/6to5/transformation/helpers/name-method.js
+++ b/lib/6to5/transformation/helpers/name-method.js
@@ -35,7 +35,7 @@ exports.property = function (node, file, scope) {
     outerDeclar: scope.getBinding(id),
   };
 
-  traverse(node, visitor, scope, state);
+  scope.traverse(node, visitor, state);
 
   if (state.selfReference) {
     // todo: support generators
diff --git a/lib/6to5/transformation/helpers/remap-async-to-generator.js b/lib/6to5/transformation/helpers/remap-async-to-generator.js
index 059d30639c..a26932eb9c 100644
--- a/lib/6to5/transformation/helpers/remap-async-to-generator.js
+++ b/lib/6to5/transformation/helpers/remap-async-to-generator.js
@@ -23,7 +23,7 @@ module.exports = function (node, callId, scope) {
   node.async = false;
   node.generator = true;
 
-  traverse(node, visitor, scope);
+  scope.traverse(node, visitor);
 
   var call = t.callExpression(callId, [node]);
   var id = node.id;
diff --git a/lib/6to5/transformation/helpers/replace-supers.js b/lib/6to5/transformation/helpers/replace-supers.js
index 107045af67..12d894d764 100644
--- a/lib/6to5/transformation/helpers/replace-supers.js
+++ b/lib/6to5/transformation/helpers/replace-supers.js
@@ -167,7 +167,7 @@ var visitor = {
 
 ReplaceSupers.prototype.traverseLevel = function (node, topLevel) {
   var state = { self: this, topLevel: topLevel };
-  traverse(node, visitor, this.scope, state);
+  this.scope.traverse(node, visitor, state);
 };
 
 /**
diff --git a/lib/6to5/transformation/modules/_default.js b/lib/6to5/transformation/modules/_default.js
index 3d06f64b9c..4e8cd7a705 100644
--- a/lib/6to5/transformation/modules/_default.js
+++ b/lib/6to5/transformation/modules/_default.js
@@ -60,7 +60,7 @@ var exportsVisitor = {
 };
 
 DefaultFormatter.prototype.getLocalExports = function () {
-  traverse(this.file.ast, exportsVisitor, this.file.scope, this);
+  this.file.scope.traverse(this.file.ast, exportsVisitor, this);
 };
 
 var importsVisitor = {
@@ -74,7 +74,7 @@ var importsVisitor = {
 };
 
 DefaultFormatter.prototype.getLocalImports = function () {
-  traverse(this.file.ast, importsVisitor, this.file.scope, this);
+   this.file.scope.traverse(this.file.ast, importsVisitor, this);
 };
 
 var remapVisitor = {
@@ -116,7 +116,7 @@ var remapVisitor = {
 
 DefaultFormatter.prototype.remapAssignments = function () {
   if (this.hasLocalImports) {
-    traverse(this.file.ast, remapVisitor, this.file.scope, this);
+    this.file.scope.traverse(this.file.ast, remapVisitor, this);
   }
 };
 
diff --git a/lib/6to5/transformation/modules/system.js b/lib/6to5/transformation/modules/system.js
index 794616c0f3..fa6c6982d7 100644
--- a/lib/6to5/transformation/modules/system.js
+++ b/lib/6to5/transformation/modules/system.js
@@ -97,7 +97,7 @@ SystemFormatter.prototype.buildRunnerSetters = function (block, hoistDeclarators
       hoistDeclarators: hoistDeclarators
     };
 
-    traverse(block, runnerSettersVisitor, scope, state);
+    scope.traverse(block, runnerSettersVisitor, state);
 
     return t.functionExpression(null, [uid], t.blockStatement(state.nodes));
   }));
@@ -182,7 +182,7 @@ SystemFormatter.prototype.transform = function (ast) {
   var returnStatement = handlerBody.pop();
 
   // hoist up all variable declarations
-  traverse(block, hoistVariablesVisitor, this.file.scope, hoistDeclarators);
+  this.file.scope.traverse(block, hoistVariablesVisitor, hoistDeclarators);
 
   if (hoistDeclarators.length) {
     var hoistDeclar = t.variableDeclaration("var", hoistDeclarators);
@@ -191,7 +191,7 @@ SystemFormatter.prototype.transform = function (ast) {
   }
 
   // hoist up function declarations for circular references
-  traverse(block, hoistFunctionsVisitor, this.file.scope, handlerBody);
+  this.file.scope.traverse(block, hoistFunctionsVisitor, handlerBody);
 
   handlerBody.push(returnStatement);
 
diff --git a/lib/6to5/transformation/transformer-pass.js b/lib/6to5/transformation/transformer-pass.js
index 5c02d6e215..e747d5f6db 100644
--- a/lib/6to5/transformation/transformer-pass.js
+++ b/lib/6to5/transformation/transformer-pass.js
@@ -89,7 +89,7 @@ TransformerPass.prototype.transform = function () {
   this.astRun("before");
 
   var state = { file: file, handlers: this.handlers, pass: this };
-  traverse(file.ast, transformVisitor, file.scope, state);
+  file.scope.traverse(file.ast, transformVisitor, state);
 
   this.astRun("after");
 };
diff --git a/lib/6to5/transformation/transformers/es6/block-scoping-tdz.js b/lib/6to5/transformation/transformers/es6/block-scoping-tdz.js
index d9b11b8923..4c58b7f74a 100644
--- a/lib/6to5/transformation/transformers/es6/block-scoping-tdz.js
+++ b/lib/6to5/transformation/transformers/es6/block-scoping-tdz.js
@@ -46,5 +46,5 @@ exports.BlockStatement = function (node, parent, scope, context, file) {
     file:    file
   };
 
-  traverse(node, visitor, scope, state);
+  scope.traverse(node, visitor, state);
 };
diff --git a/lib/6to5/transformation/transformers/es6/block-scoping.js b/lib/6to5/transformation/transformers/es6/block-scoping.js
index 40daed0dae..8a1c7775b3 100644
--- a/lib/6to5/transformation/transformers/es6/block-scoping.js
+++ b/lib/6to5/transformation/transformers/es6/block-scoping.js
@@ -130,7 +130,7 @@ var replaceVisitor = {
 
 function traverseReplace(node, parent, scope, remaps) {
   replace(node, parent, scope, null, remaps);
-  traverse(node, replaceVisitor, scope, remaps);
+  scope.traverse(node, replaceVisitor, remaps);
 }
 
 /**
@@ -176,7 +176,7 @@ BlockScoping.prototype.remap = function () {
     traverseReplace(loopParent.update, loopParent, scope, remaps);
   }
 
-  traverse(this.block, replaceVisitor, scope, remaps);
+  scope.traverse(this.block, replaceVisitor, remaps);
 };
 
 /**
@@ -243,7 +243,7 @@ var letReferenceFunctionVisitor = {
 var letReferenceBlockVisitor = {
   enter: function (node, parent, scope, context, state) {
     if (t.isFunction(node)) {
-      traverse(node, letReferenceFunctionVisitor, scope, state);
+      scope.traverse(node, letReferenceFunctionVisitor, state);
       return context.skip();
     }
   }
@@ -296,7 +296,7 @@ BlockScoping.prototype.getLetReferences = function () {
 
   // traverse through this block, stopping on functions and checking if they
   // contain any local let references
-  traverse(this.block, letReferenceBlockVisitor, this.scope, state);
+  this.scope.traverse(this.block, letReferenceBlockVisitor, state);
 
   return state.closurify;
 };
@@ -315,7 +315,7 @@ var loopVisitor = {
 
     if (t.isLoop(node)) {
       state.ignoreLabeless = true;
-      traverse(node, loopVisitor, scope, state);
+      scope.traverse(node, loopVisitor, state);
       state.ignoreLabeless = false;
     }
 
@@ -388,8 +388,8 @@ BlockScoping.prototype.checkLoop = function () {
     map:              {}
   };
 
-  traverse(this.block, loopLabelVisitor, this.scope, state);
-  traverse(this.block, loopVisitor, this.scope, state);
+  this.scope.traverse(this.block, loopLabelVisitor, state);
+  this.scope.traverse(this.block, loopVisitor, state);
 
   return state;
 };
diff --git a/lib/6to5/transformation/transformers/es6/constants.js b/lib/6to5/transformation/transformers/es6/constants.js
index cb7101faf2..165ff12512 100644
--- a/lib/6to5/transformation/transformers/es6/constants.js
+++ b/lib/6to5/transformation/transformers/es6/constants.js
@@ -37,7 +37,7 @@ var visitor = {
 };
 
 exports.Scope = function (node, parent, scope, context, file) {
-  traverse(node, visitor, scope, {
+  scope.traverse(node, visitor, {
     constants: scope.getAllDeclarationsOfKind("const"),
     file:      file
   });
diff --git a/lib/6to5/transformation/transformers/es6/parameters.default.js b/lib/6to5/transformation/transformers/es6/parameters.default.js
index 2854e572d7..af715ae005 100644
--- a/lib/6to5/transformation/transformers/es6/parameters.default.js
+++ b/lib/6to5/transformation/transformers/es6/parameters.default.js
@@ -55,7 +55,7 @@ exports.Function = function (node, parent, scope) {
       if (t.isIdentifier(right) && scope.hasOwnReference(right.name)) {
         state.iife = true;
       } else {
-        traverse(right, iifeVisitor, scope, state);
+        scope.traverse(right, iifeVisitor, state);
       }
     }
 
diff --git a/lib/6to5/transformation/transformers/internal/alias-functions.js b/lib/6to5/transformation/transformers/internal/alias-functions.js
index 640f334f9c..8f53bc6cda 100644
--- a/lib/6to5/transformation/transformers/internal/alias-functions.js
+++ b/lib/6to5/transformation/transformers/internal/alias-functions.js
@@ -37,7 +37,7 @@ var functionVisitor = {
     }
 
     // traverse all child nodes of this function and find `arguments` and `this`
-    traverse(node, functionChildrenVisitor, scope, state);
+    scope.traverse(node, functionChildrenVisitor, state);
 
     return context.skip();
   }
@@ -58,7 +58,7 @@ var go = function (getBody, node, scope) {
 
   // traverse the function and find all alias functions so we can alias
   // `arguments` and `this` if necessary
-  traverse(node, functionVisitor, scope, state);
+  scope.traverse(node, functionVisitor, state);
 
   var body;
 
diff --git a/lib/6to5/transformation/transformers/other/self-contained.js b/lib/6to5/transformation/transformers/other/self-contained.js
index 4f60e3d015..9be7d45e33 100644
--- a/lib/6to5/transformation/transformers/other/self-contained.js
+++ b/lib/6to5/transformation/transformers/other/self-contained.js
@@ -77,7 +77,7 @@ exports.ast = {
   },
 
   after: function (ast, file) {
-    traverse(ast, astVisitor, null, file);
+    file.scope.traverse(ast, astVisitor, file);
   }
 };
 
diff --git a/lib/6to5/transformation/transformers/playground/object-getter-memoization.js b/lib/6to5/transformation/transformers/playground/object-getter-memoization.js
index e27da96702..55dff3d130 100644
--- a/lib/6to5/transformation/transformers/playground/object-getter-memoization.js
+++ b/lib/6to5/transformation/transformers/playground/object-getter-memoization.js
@@ -39,5 +39,5 @@ exports.MethodDefinition = function (node, parent, scope, context, file) {
     file: file
   };
 
-  traverse(value, visitor, scope, state);
+  scope.traverse(value, visitor, state);
 };
diff --git a/lib/6to5/traverse/scope.js b/lib/6to5/traverse/scope.js
index 1f05f05b86..6a35054c9c 100644
--- a/lib/6to5/traverse/scope.js
+++ b/lib/6to5/traverse/scope.js
@@ -308,7 +308,7 @@ Scope.prototype.crawl = function () {
   // Program, BlockStatement - let variables
 
   if (t.isBlockStatement(block) || t.isProgram(block)) {
-    traverse(block, blockVariableVisitor, this, this);
+    this.traverse(block, blockVariableVisitor, this);
   }
 
   // CatchClause - param
@@ -334,7 +334,7 @@ Scope.prototype.crawl = function () {
   // Program, Function - var variables
 
   if (t.isProgram(block) || t.isFunction(block)) {
-    traverse(block, functionVariableVisitor, this, {
+    this.traverse(block, functionVariableVisitor, {
       blockId: block.id,
       scope:   this
     });
@@ -351,7 +351,7 @@ Scope.prototype.crawl = function () {
   // Program
 
   if (t.isProgram(block)) {
-    traverse(block, programReferenceVisitor, this, this);
+    this.traverse(block, programReferenceVisitor, this);
   }
 };