diff --git a/.gitignore b/.gitignore
index 2d415e1..73f68bf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,4 @@ npm-debug.log
 apiref
 bower_components
 dist
+report
diff --git a/gulpfile.js b/gulpfile.js
index 142f8db..aa98843 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -96,7 +96,8 @@ gulp.task('lint', function() {
 gulp.task('browser', ['errors'], function() {
   return gulp.src('index.js')
     .pipe(browserify({
-      insertGlobals: true
+      insertGlobals: true,
+      standalone: 'bitcore'
     }))
     .pipe(rename('bitcore.js'))
     .pipe(gulp.dest('browser'));
@@ -110,7 +111,7 @@ gulp.task('browser-all', ['errors'], function(callback) {
   runSequence(['browser'], ['browser-test'], callback);
 });
 
-gulp.task('karma', ['browser-test'], testKarma);
+gulp.task('karma', ['browser-all'], testKarma);
 
 gulp.task('errors', shell.task([
   'node ./lib/errors/build.js'
diff --git a/lib/errors/build.js b/lib/errors/build.js
index 7130c0f..cbd44f9 100644
--- a/lib/errors/build.js
+++ b/lib/errors/build.js
@@ -14,10 +14,10 @@ var formatMessage = function(message) {
 var defineElement = function(fullName, baseClass, message) {
   return fullName + ' = function() {\n' +
          '  this.message = ' + formatMessage(message) + ';\n' +
-         '  ' + baseClass + '.call(this, this.message);\n' +
-         '  this.name = "' + fullName + '";\n' +
+         '  this.stack = this.message + \'\\n\' + (new Error()).stack;\n' +
          '};\n' +
-         'inherits(' + fullName + ', ' + baseClass + ');\n\n';
+         fullName + '.prototype = Object.create(' + baseClass + '.prototype);\n' +
+         fullName + '.prototype.name = "' + fullName + '";\n\n';
 };
 
 var traverseNode = function(baseClass, errorDefinition) {
diff --git a/lib/errors/spec.js b/lib/errors/spec.js
index cc3f1b9..6a0453b 100644
--- a/lib/errors/spec.js
+++ b/lib/errors/spec.js
@@ -4,7 +4,7 @@ module.exports = [{
   errors: [
     {
       name: 'InvalidArgument',
-      message: 'HDPrivateKey: Invalid Argument {0}, expected {1} but got {2}',
+      message: 'Invalid Argument {0}, expected {1} but got {2}',
       errors: [{
         name: 'InvalidB58Char',
         message: 'Invalid Base58 character: {0} in {1}'
@@ -48,7 +48,7 @@ module.exports = [{
   errors: [
     {
       name: 'InvalidArgument',
-      message: 'HDPublicKey: Invalid Argument {0}, expected {1} but got {2}',
+      message: 'Invalid Argument {0}, expected {1} but got {2}',
       errors: [{
         name: 'ArgumentIsPrivateExtended',
         message: 'Argument is an extended private key: {0}'
diff --git a/npm-shrinkwrap.json b/npm-shrinkwrap.json
index b619ac3..eb62ce9 100644
--- a/npm-shrinkwrap.json
+++ b/npm-shrinkwrap.json
@@ -38,6 +38,11 @@
         }
       }
     },
+    "inherits": {
+      "version": "2.0.1",
+      "from": "inherits@2.0.1",
+      "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.1.tgz"
+    },
     "hash.js": {
       "version": "0.3.2",
       "from": "hash.js@0.3.2",
@@ -49,6 +54,11 @@
         }
       }
     },
+    "lodash": {
+       "version": "2.4.1",
+       "from": "lodash@=2.4.1",
+       "resolved": "https://registry.npmjs.org/lodash/-/lodash-2.4.1.tgz"
+    },
     "sha512": {
       "version": "0.0.1",
       "from": "sha512@=0.0.1",
diff --git a/package.json b/package.json
index 5ae6407..9b56679 100644
--- a/package.json
+++ b/package.json
@@ -91,14 +91,11 @@
     "gulp-mocha": "^2.0.0",
     "gulp-rename": "^1.2.0",
     "gulp-shell": "^0.2.10",
-    "inherits": "^2.0.1",
-    "lodash": "^2.4.1",
     "mocha": "~2.0.1",
     "run-sequence": "^1.0.2",
     "karma": "^0.12.28",
     "karma-firefox-launcher": "^0.1.3",
     "karma-mocha": "^0.1.9",
-    "lodash": "^2.4.1",
     "mocha": "~2.0.1",
     "run-sequence": "^1.0.2"
   },