diff --git a/run-all-tests.js b/run-all-tests.js
index 4ba66ab..37e55c2 100644
--- a/run-all-tests.js
+++ b/run-all-tests.js
@@ -10,7 +10,16 @@ var path = require('path');
 require('json5/lib/require');
 
 
-module.exports = function (mpPath, beforeRunningAnyTests, eachTestSuite, done){
+module.exports = function (mpPath, singleMachineToTest, beforeRunningAnyTests, eachTestSuite, done){
+  // Support optional singleMachineToTest
+  if (arguments.length < 4) {
+    singleMachineToTest = false;
+    done = arguments[3];
+    eachTestSuite = arguments[2];
+    beforeRunningAnyTests = arguments[1];
+  } else {
+    console.warn('Testing single machine:', singleMachineToTest);
+  }
 
   // Use provided machinepack path
   var mainPath = path.resolve(mpPath);
@@ -39,6 +48,14 @@ module.exports = function (mpPath, beforeRunningAnyTests, eachTestSuite, done){
       return done(new Error(util.format('Encountered error loading or parsing pack\'s package.json file (located at `%s`). Details:\n',packageJsonPath, e)));
     }
 
+    if (singleMachineToTest) {
+      if (machineIdentities.indexOf(singleMachineToTest) == -1) {
+        return done(new Error(util.format('Unknown machine "%s"', singleMachineToTest)));
+      }
+
+      machineIdentities = [singleMachineToTest];
+    }
+
     var missingSuites = [];
     async.map(machineIdentities, function (machineIdentity, next_machineSuite){