diff --git a/tools/commands.js b/tools/commands.js
index 90aa905b19..6dc046acbc 100644
--- a/tools/commands.js
+++ b/tools/commands.js
@@ -601,8 +601,8 @@ main.registerCommand({
 
   if (options.args.length === 0) {
     // localhost mode
-    var mongo_runner = require(path.join(__dirname, 'mongo_runner.js'));
-    var mongoPort = mongo_runner.findMongoPort(options.appDir);
+    var mongoRunner = require(path.join(__dirname, 'mongo-runner.js'));
+    var mongoPort = mongoRunner.findMongoPort(options.appDir);
     if (! mongoPort) {
       process.stdout.write(
 "mongo: Meteor isn't running.\n" +
@@ -656,8 +656,8 @@ main.registerCommand({
     return 1;
   }
 
-  var mongo_runner = require(path.join(__dirname, 'mongo_runner.js'));
-  var isRunning = !! mongo_runner.findMongoPort(options.appDir);
+  var mongoRunner = require(path.join(__dirname, 'mongo-runner.js'));
+  var isRunning = !! mongoRunner.findMongoPort(options.appDir);
   if (isRunning) {
     process.stderr.write(
 "reset: Meteor is running.\n" +
diff --git a/tools/meteor_npm.js b/tools/meteor-npm.js
similarity index 100%
rename from tools/meteor_npm.js
rename to tools/meteor-npm.js
diff --git a/tools/mongo_exit_codes.js b/tools/mongo-exit-codes.js
similarity index 100%
rename from tools/mongo_exit_codes.js
rename to tools/mongo-exit-codes.js
diff --git a/tools/mongo_runner.js b/tools/mongo-runner.js
similarity index 100%
rename from tools/mongo_runner.js
rename to tools/mongo-runner.js
diff --git a/tools/packages.js b/tools/packages.js
index 5c5547af78..43c0ba982d 100644
--- a/tools/packages.js
+++ b/tools/packages.js
@@ -7,7 +7,7 @@ var bundler = require('./bundler.js');
 var Builder = require('./builder.js');
 var project = require('./project.js');
 var buildmessage = require('./buildmessage.js');
-var meteorNpm = require('./meteor_npm.js');
+var meteorNpm = require('./meteor-npm.js');
 var archinfo = require(path.join(__dirname, 'archinfo.js'));
 var linker = require(path.join(__dirname, 'linker.js'));
 var unipackage = require('./unipackage.js');
diff --git a/tools/run.js b/tools/run.js
index acd14c24df..dfbcf5f022 100644
--- a/tools/run.js
+++ b/tools/run.js
@@ -12,8 +12,8 @@ var updater = require('./updater.js');
 var bundler = require('./bundler.js');
 var Builder = require('./builder.js');
 var buildmessage = require('./buildmessage.js');
-var mongo_runner = require('./mongo_runner.js');
-var mongoExitCodes = require('./mongo_exit_codes.js');
+var mongoRunner = require('./mongo-runner.js');
+var mongoExitCodes = require('./mongo-exit-codes.js');
 var unipackage = require('./unipackage.js');
 var release = require('./release.js');
 
@@ -604,7 +604,7 @@ exports.run = function (appDir, options) {
   var mongoStartupPrintTimer;
   var launch = function () {
     Fiber(function () {
-      Status.mongoHandle = mongo_runner.launchMongo({
+      Status.mongoHandle = mongoRunner.launchMongo({
         appDir: appDir,
         port: mongoPort,
         onListen: function () { // On Mongo startup complete
diff --git a/tools/tests/test_bundler.js b/tools/tests/test_bundler.js
index 4613370442..5700cbcc73 100644
--- a/tools/tests/test_bundler.js
+++ b/tools/tests/test_bundler.js
@@ -27,7 +27,7 @@ var lastTmpDir;
 Fiber(function () {
   try {
     // print calls to `npm`
-    require(path.join(__dirname, '..', 'meteor_npm.js'))._printNpmCalls = true;
+    require(path.join(__dirname, '..', 'meteor-npm.js'))._printNpmCalls = true;
 
     /// RUN TESTS
     require(path.join(__dirname, 'test_bundler_assets.js'));
diff --git a/tools/tests/test_bundler_npm.js b/tools/tests/test_bundler_npm.js
index 420e207782..626681379f 100644
--- a/tools/tests/test_bundler_npm.js
+++ b/tools/tests/test_bundler_npm.js
@@ -1,4 +1,4 @@
-var meteorNpm = require(path.join(__dirname, '..', 'meteor_npm.js'));
+var meteorNpm = require(path.join(__dirname, '..', 'meteor-npm.js'));
 
 ///
 /// TEST PACKAGE DIR