diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index e7c2badea5..73c10aef1f 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -17,7 +17,7 @@ function File(opts) {
   this.ast            = {};
 }
 
-File.declarations = [
+File.helpers = [
   "inherits",
   "defaults",
   "prototype-properties",
@@ -33,7 +33,7 @@ File.declarations = [
   "async-to-generator"
 ];
 
-File.excludeDeclarationsFromRuntime = [
+File.excludeHelpersFromRuntime = [
   "async-to-generator"
 ];
 
@@ -121,7 +121,7 @@ File.prototype.toArray = function (node, i) {
   if (t.isArrayExpression(node)) {
     return node;
   } else if (t.isIdentifier(node) && node.name === "arguments") {
-    return t.callExpression(t.memberExpression(this.addDeclaration("slice"), t.identifier("call")), [node]);
+    return t.callExpression(t.memberExpression(this.addHelper("slice"), t.identifier("call")), [node]);
   } else {
     var declarationName = "to-array";
     var args = [node];
@@ -129,7 +129,7 @@ File.prototype.toArray = function (node, i) {
       args.push(t.literal(i));
       declarationName = "sliced-to-array";
     }
-    return t.callExpression(this.addDeclaration(declarationName), args);
+    return t.callExpression(this.addHelper(declarationName), args);
   }
 };
 
@@ -167,8 +167,8 @@ File.prototype.addImport = function (id, source) {
   this.dynamicImports.push(declar);
 };
 
-File.prototype.addDeclaration = function (name) {
-  if (!_.contains(File.declarations, name)) {
+File.prototype.addHelper = function (name) {
+  if (!_.contains(File.helpers, name)) {
     throw new ReferenceError("unknown declaration " + name);
   }
 
@@ -179,7 +179,7 @@ File.prototype.addDeclaration = function (name) {
 
   var ref;
   var runtimeNamespace = this.opts.runtime;
-  if (runtimeNamespace && !_.contains(File.excludeDeclarationsFromRuntime, name)) {
+  if (runtimeNamespace && !_.contains(File.excludeHelpersFromRuntime, name)) {
     name = t.identifier(t.toIdentifier(name));
     return t.memberExpression(t.identifier(runtimeNamespace), name);
   } else {
diff --git a/lib/6to5/runtime-generator.js b/lib/6to5/runtime-generator.js
index 59ad533466..ec9924ecc5 100644
--- a/lib/6to5/runtime-generator.js
+++ b/lib/6to5/runtime-generator.js
@@ -18,8 +18,8 @@ module.exports = function (namespace) {
     )
   ]));
 
-  _.each(File.declarations, function (name) {
-    if (_.contains(File.excludeDeclarationsFromRuntime, name)) {
+  _.each(File.helpers, function (name) {
+    if (_.contains(File.excludeHelpersFromRuntime, name)) {
       return false;
     }
 
diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index 48ba860fe5..bb4b4137ae 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -85,7 +85,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
     // import * as bar from "foo";
   } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
     // import foo from "foo";
-    ref = t.callExpression(this.file.addDeclaration("interop-require"), [ref]);
+    ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
   } else {
     // import {foo} from "foo";
     ref = t.memberExpression(ref, specifier.id, false);
diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index d2735ecd2d..d527e49e73 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -26,7 +26,7 @@ CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes)
   if (t.isSpecifierDefault(specifier)) {
     nodes.push(t.variableDeclaration("var", [
       t.variableDeclarator(variableName,
-        t.callExpression(this.file.addDeclaration("interop-require"), [util.template("require", {
+        t.callExpression(this.file.addHelper("interop-require"), [util.template("require", {
           MODULE_NAME: node.source
         })])
       )
diff --git a/lib/6to5/transformation/transformers/es6-classes.js b/lib/6to5/transformation/transformers/es6-classes.js
index 62048733fa..f0922ebb8b 100644
--- a/lib/6to5/transformation/transformers/es6-classes.js
+++ b/lib/6to5/transformation/transformers/es6-classes.js
@@ -96,7 +96,7 @@ Class.prototype.run = function () {
     superName = superRef;
 
     this.superName = superName;
-    body.push(t.expressionStatement(t.callExpression(file.addDeclaration("inherits"), [className, superName])));
+    body.push(t.expressionStatement(t.callExpression(file.addHelper("inherits"), [className, superName])));
   }
 
   this.buildBody();
@@ -175,7 +175,7 @@ Class.prototype.buildBody = function () {
     if (instanceProps) args.push(instanceProps);
 
     body.push(t.expressionStatement(
-      t.callExpression(this.file.addDeclaration("prototype-properties"), args)
+      t.callExpression(this.file.addHelper("prototype-properties"), args)
     ));
   }
 };
diff --git a/lib/6to5/transformation/transformers/es6-computed-property-names.js b/lib/6to5/transformation/transformers/es6-computed-property-names.js
index 2ae78da58f..57312902e5 100644
--- a/lib/6to5/transformation/transformers/es6-computed-property-names.js
+++ b/lib/6to5/transformation/transformers/es6-computed-property-names.js
@@ -68,7 +68,7 @@ exports.ObjectExpression = function (node, parent, file, scope) {
         prop.value
       );
     } else {
-      bodyNode = t.callExpression(file.addDeclaration("define-property"), [objId, key, prop.value]);
+      bodyNode = t.callExpression(file.addHelper("define-property"), [objId, key, prop.value]);
     }
 
     body.push(t.expressionStatement(bodyNode));
diff --git a/lib/6to5/transformation/transformers/es6-destructuring.js b/lib/6to5/transformation/transformers/es6-destructuring.js
index 8858790d77..c8b7bffb36 100644
--- a/lib/6to5/transformation/transformers/es6-destructuring.js
+++ b/lib/6to5/transformation/transformers/es6-destructuring.js
@@ -45,7 +45,7 @@ var pushObjectPattern = function (opts, nodes, pattern, parentId) {
         }
         keys = t.arrayExpression(keys);
 
-        var value = t.callExpression(opts.file.addDeclaration("object-without-properties"), [parentId, keys]);
+        var value = t.callExpression(opts.file.addHelper("object-without-properties"), [parentId, keys]);
         nodes.push(buildVariableAssign(opts, prop.argument, value));
     } else {
       var pattern2   = prop.value;
diff --git a/lib/6to5/transformation/transformers/es6-spread.js b/lib/6to5/transformation/transformers/es6-spread.js
index bde318aa6d..214a765f03 100644
--- a/lib/6to5/transformation/transformers/es6-spread.js
+++ b/lib/6to5/transformation/transformers/es6-spread.js
@@ -107,5 +107,5 @@ exports.NewExpression = function (node, parent, file) {
     args = first;
   }
 
-  return t.callExpression(file.addDeclaration("apply-constructor"), [node.callee, args]);
+  return t.callExpression(file.addHelper("apply-constructor"), [node.callee, args]);
 };
diff --git a/lib/6to5/transformation/transformers/es6-template-literals.js b/lib/6to5/transformation/transformers/es6-template-literals.js
index 5a5f4ce445..4be21d4269 100644
--- a/lib/6to5/transformation/transformers/es6-template-literals.js
+++ b/lib/6to5/transformation/transformers/es6-template-literals.js
@@ -17,7 +17,7 @@ exports.TaggedTemplateExpression = function (node, parent, file) {
     raw.push(t.literal(elem.value.raw));
   }
 
-  args.push(t.callExpression(file.addDeclaration("tagged-template-literal"), [
+  args.push(t.callExpression(file.addHelper("tagged-template-literal"), [
     t.arrayExpression(strings),
     t.arrayExpression(raw)
   ]));
diff --git a/lib/6to5/transformation/transformers/optional-async-to-generator.js b/lib/6to5/transformation/transformers/optional-async-to-generator.js
index 9886b8d6bd..551c9f7c71 100644
--- a/lib/6to5/transformation/transformers/optional-async-to-generator.js
+++ b/lib/6to5/transformation/transformers/optional-async-to-generator.js
@@ -7,5 +7,5 @@ exports.manipulateOptions = bluebirdCoroutines.manipulateOptions;
 exports.Function = function (node, parent, file) {
   if (!node.async || node.generator) return;
 
-  return bluebirdCoroutines._Function(node, file.addDeclaration("async-to-generator"));
+  return bluebirdCoroutines._Function(node, file.addHelper("async-to-generator"));
 };
diff --git a/lib/6to5/transformation/transformers/optional-proto-to-assign.js b/lib/6to5/transformation/transformers/optional-proto-to-assign.js
index 3101abf474..0f18f5a547 100644
--- a/lib/6to5/transformation/transformers/optional-proto-to-assign.js
+++ b/lib/6to5/transformation/transformers/optional-proto-to-assign.js
@@ -13,7 +13,7 @@ var isProtoAssignmentExpression = function (node) {
 };
 
 var buildDefaultsCallExpression = function (expr, ref, file) {
-  return t.expressionStatement(t.callExpression(file.addDeclaration("defaults"), [ref, expr.right]));
+  return t.expressionStatement(t.callExpression(file.addHelper("defaults"), [ref, expr.right]));
 };
 
 exports.optional = true;
diff --git a/lib/6to5/transformation/transformers/playground-memoization-operator.js b/lib/6to5/transformation/transformers/playground-memoization-operator.js
index c8cf35b4d8..d8aad48236 100644
--- a/lib/6to5/transformation/transformers/playground-memoization-operator.js
+++ b/lib/6to5/transformation/transformers/playground-memoization-operator.js
@@ -30,7 +30,7 @@ var buildHasOwn = function (obj, prop, file) {
   return t.unaryExpression(
     "!",
     t.callExpression(
-      t.memberExpression(file.addDeclaration("has-own"), t.identifier("call")),
+      t.memberExpression(file.addHelper("has-own"), t.identifier("call")),
       [obj, prop]
     ),
     true
diff --git a/lib/6to5/transformation/transformers/playground-object-getter-memoization.js b/lib/6to5/transformation/transformers/playground-object-getter-memoization.js
index 3fdb70beb6..9c3f0bb6d0 100644
--- a/lib/6to5/transformation/transformers/playground-object-getter-memoization.js
+++ b/lib/6to5/transformation/transformers/playground-object-getter-memoization.js
@@ -20,7 +20,7 @@ exports.MethodDefinition = function (node, parent, file) {
       if (t.isFunction(node)) return;
 
       if (t.isReturnStatement(node) && node.argument) {
-        node.argument = t.memberExpression(t.callExpression(file.addDeclaration("define-property"), [
+        node.argument = t.memberExpression(t.callExpression(file.addHelper("define-property"), [
           t.thisExpression(),
           key,
           node.argument
diff --git a/test/api.js b/test/api.js
index 260c7f4483..5559760643 100644
--- a/test/api.js
+++ b/test/api.js
@@ -13,10 +13,10 @@ suite("api", function () {
     assert.ok(!result.ast);
   });
 
-  test("addDeclaration unknown", function () {
+  test("addHelper unknown", function () {
     var file = new File;
     assert.throws(function () {
-      file.addDeclaration("foob");
+      file.addHelper("foob");
     }, /unknown declaration foob/);
   });
 });