diff --git a/CHANGELOG-6to5.md b/CHANGELOG-6to5.md
index 4d3af0e2ad..6005a2db3a 100644
--- a/CHANGELOG-6to5.md
+++ b/CHANGELOG-6to5.md
@@ -7,7 +7,7 @@
  * **Bug Fix**
   * Fix temp variables not being properly pushed inside of `while` loops.
  * **New Feature**
-  * Add `auxilaryComment`/`--auxilary-comment` option that prepends comments to auxilary helpers.
+  * Add `auxiliaryComment`/`--auxiliary-comment` option that prepends comments to auxiliary helpers.
 
 ## 3.6.5
 
diff --git a/bin/babel/index.js b/bin/babel/index.js
index 7d89de89f7..7f8256c6fc 100755
--- a/bin/babel/index.js
+++ b/bin/babel/index.js
@@ -26,7 +26,7 @@ commander.option("-c, --remove-comments", "Remove comments from the compiled cod
 commander.option("-M, --module-ids", "Insert module id in modules", false);
 commander.option("-R, --react-compat", "Makes the react transformer produce pre-v0.12 code");
 commander.option("--keep-module-id-extensions", "Keep extensions when generating module ids", false);
-commander.option("-a, --auxilary-comment [comment]", "Comment text to prepend to all auxilary code");
+commander.option("-a, --auxiliary-comment [comment]", "Comment text to prepend to all auxiliary code");
 
 commander.on("--help", function () {
   var outKeys = function (title, obj) {
@@ -100,7 +100,7 @@ if (errors.length) {
 
 exports.opts = {
   keepModuleIdExtensions: commander.keepModuleIdExtensions,
-  auxilaryComment:        commander.auxilaryComment,
+  auxiliaryComment:       commander.auxiliaryComment,
   externalHelpers:        commander.externalHelpers,
   sourceMapName:          commander.outFile,
   experimental:           commander.experimental,
diff --git a/lib/babel/transformation/file.js b/lib/babel/transformation/file.js
index 74eb9e5916..76c994f299 100644
--- a/lib/babel/transformation/file.js
+++ b/lib/babel/transformation/file.js
@@ -87,7 +87,7 @@ File.validOptions = [
   "experimental",
   "resolveModuleSource",
   "externalHelpers",
-  "auxilaryComment",
+  "auxiliaryComment",
 
   // these are used by plugins
   "ignore",
@@ -302,8 +302,8 @@ File.prototype.isConsequenceExpressionStatement = function (node) {
   return t.isExpressionStatement(node) && this.lastStatements.indexOf(node) >= 0;
 };
 
-File.prototype.attachAuxilaryComment = function (node) {
-  var comment = this.opts.auxilaryComment;
+File.prototype.attachAuxiliaryComment = function (node) {
+  var comment = this.opts.auxiliaryComment;
   if (comment) {
     node.leadingComments = node.leadingComments || [];
     node.leadingComments.push({
diff --git a/lib/babel/transformation/transformers/internal/declarations.js b/lib/babel/transformation/transformers/internal/declarations.js
index 0e3f3335ba..cd07030b56 100644
--- a/lib/babel/transformation/transformers/internal/declarations.js
+++ b/lib/babel/transformation/transformers/internal/declarations.js
@@ -20,7 +20,7 @@ exports.Program = function (node, parent, scope, file) {
       var declarNode = t.variableDeclarator(declar.id, declar.init);
 
       if (declar.init) {
-        node.body.unshift(file.attachAuxilaryComment(t.variableDeclaration(kind, [declarNode])));
+        node.body.unshift(file.attachAuxiliaryComment(t.variableDeclaration(kind, [declarNode])));
       } else {
         kinds[kind] = kinds[kind] || [];
         kinds[kind].push(declarNode);
@@ -28,7 +28,7 @@ exports.Program = function (node, parent, scope, file) {
     }
 
     for (kind in kinds) {
-      node.body.unshift(file.attachAuxilaryComment(t.variableDeclaration(kind, kinds[kind])));
+      node.body.unshift(file.attachAuxiliaryComment(t.variableDeclaration(kind, kinds[kind])));
     }
   });