diff --git a/src/extensibility/node/ExtensionManagerDomain.js b/src/extensibility/node/ExtensionManagerDomain.js
index b6732e5fdf5..818779b33f8 100644
--- a/src/extensibility/node/ExtensionManagerDomain.js
+++ b/src/extensibility/node/ExtensionManagerDomain.js
@@ -70,7 +70,7 @@ var pendingDownloads = {};
  */
 function validateName(name) {
     // "This must be a unique, lowercase alpha-numeric name without spaces. It may include "." or "_" or "-" characters."
-    if (/^[a-z._\-]+$/.exec(name)) {
+    if (/^[a-z0-9._\-]+$/.exec(name)) {
         return true;
     }
     return false;
@@ -104,7 +104,7 @@ function _cmdValidate(path, callback) {
         }
         var callbackCalled = false;
         var metadata;
-        var foundMain = false;
+        var foundMainIn = null;
         var errors = [];
         var commonPrefix = null;
         
@@ -183,7 +183,7 @@ function _cmdValidate(path, callback) {
                             }
                         });
                 } else if (fileName === "main.js") {
-                    foundMain = true;
+                    foundMainIn = commonPrefix;
                 }
             })
             .on("end", function () {
@@ -195,7 +195,7 @@ function _cmdValidate(path, callback) {
                     return;
                 }
                 
-                if (!foundMain) {
+                if (foundMainIn === null || foundMainIn !== commonPrefix) {
                     errors.push([Errors.MISSING_MAIN, path]);
                 }
                 
diff --git a/src/extensibility/node/spec/Validation.spec.js b/src/extensibility/node/spec/Validation.spec.js
index de73ad0823e..dc380652f11 100644
--- a/src/extensibility/node/spec/Validation.spec.js
+++ b/src/extensibility/node/spec/Validation.spec.js
@@ -49,6 +49,7 @@ var basicValidExtension = path.join(testFilesDirectory, "basic-valid-extension.z
     oneLevelDown        = path.join(testFilesDirectory, "one-level-extension-master.zip"),
     bogusTopDir         = path.join(testFilesDirectory, "bogus-top-dir.zip"),
     badname             = path.join(testFilesDirectory, "badname.zip"),
+    mainInDirectory     = path.join(testFilesDirectory, "main-in-directory.zip"),
     invalidVersion      = path.join(testFilesDirectory, "invalid-version.zip");
 
 describe("Package Validation", function () {
@@ -168,4 +169,14 @@ describe("Package Validation", function () {
             done();
         });
     });
+    
+    it("should complain about files that don't have main in the top dir", function (done) {
+        ExtensionsDomain._cmdValidate(mainInDirectory, function (err, result) {
+            expect(err).toBeNull();
+            var errors = result.errors;
+            expect(errors.length).toEqual(1);
+            expect(errors[0][0]).toEqual("MISSING_MAIN");
+            done();
+        });
+    });
 });
\ No newline at end of file
diff --git a/tasks/update-sprint-number.js b/tasks/update-sprint-number.js
index 18d612b1a68..10b563dc042 100644
--- a/tasks/update-sprint-number.js
+++ b/tasks/update-sprint-number.js
@@ -20,7 +20,8 @@
  * DEALINGS IN THE SOFTWARE.
  * 
  */
- /*global module, require*/
+/*global module, require*/
+
 module.exports = function (grunt) {
     "use strict";
 
@@ -31,14 +32,15 @@ module.exports = function (grunt) {
     grunt.registerTask('update-sprint-number', function () {
         var path        = "package.json",
             packageJSON = grunt.file.readJSON(path),
-            sprint      = grunt.option("sprint") || 0;
+            sprint      = grunt.option("sprint") || 0,
+            versionNumberRegexp = /([0-9]+\.)([0-9]+)([\.\-a-zA-Z0-9]*)?/;
 
         if (!sprint) {
             grunt.fail.fatal("Please specify a sprint. e.g. grunt update-sprint-number --sprint=21");
         }
         
-        packageJSON.version = packageJSON.version.replace(/([0-9]+\.)([0-9]+)([\.\-a-zA-Z0-9]*)?/, "$1" + sprint + "$3");
-        packageJSON.apiVersion = packageJSON.apiVersion.replace(/([0-9]+\.)([0-9]+)([\.\-a-zA-Z0-9]*)?/, "$1" + sprint + "$3");
+        packageJSON.version = packageJSON.version.replace(versionNumberRegexp, "$1" + sprint + "$3");
+        packageJSON.apiVersion = packageJSON.apiVersion.replace(versionNumberRegexp, "$1" + sprint + "$3");
 
         common.writeJSON(grunt, path, packageJSON);
     });
diff --git a/test/spec/extension-test-files/main-in-directory.zip b/test/spec/extension-test-files/main-in-directory.zip
new file mode 100644
index 00000000000..87c7c1aa07d
Binary files /dev/null and b/test/spec/extension-test-files/main-in-directory.zip differ