diff --git a/karma-coverage.conf.js b/karma-coverage.conf.js
index 327cc067..3f37b92d 100644
--- a/karma-coverage.conf.js
+++ b/karma-coverage.conf.js
@@ -27,6 +27,12 @@ module.exports = function(config) {
 				included: true,
 				served: true
 			},
+			{
+				pattern: 'packages/metal-soy-bundle/build/bundle.js',
+				watched: false,
+				included: false,
+				served: true
+			},
 			{
 				pattern: 'packages/metal-web-component/node_modules/babel-polyfill/dist/polyfill.min.js',
 				watched: false,
@@ -65,6 +71,7 @@ module.exports = function(config) {
 			'packages/metal-incremental-dom/src/incremental-dom.js': ['browserify'],
 			'packages/metal-incremental-dom/lib/incremental-dom.js': ['browserify'],
 			'packages/metal-soy-bundle/lib/bundle.js': ['browserify'],
+			'packages/metal-soy-bundle/build/bundle.js': ['browserify'],
 			'packages/metal*/test/**/*.js': ['browserify']
 		},
 
diff --git a/karma-sauce.conf.js b/karma-sauce.conf.js
index 6615fb81..4ef18283 100644
--- a/karma-sauce.conf.js
+++ b/karma-sauce.conf.js
@@ -27,6 +27,12 @@ module.exports = function(config) {
 				included: true,
 				served: true
 			},
+			{
+				pattern: 'packages/metal-soy-bundle/build/bundle.js',
+				watched: false,
+				included: false,
+				served: true
+			},
 			{
 				pattern: 'packages/metal-web-component/node_modules/babel-polyfill/dist/polyfill.min.js',
 				watched: false,
@@ -65,6 +71,7 @@ module.exports = function(config) {
 			'packages/metal-incremental-dom/src/incremental-dom.js': ['browserify'],
 			'packages/metal-incremental-dom/lib/incremental-dom.js': ['browserify'],
 			'packages/metal-soy/node_modules/metal-soy-bundle/lib/bundle.js': ['browserify'],
+			'packages/metal-soy-bundle/build/bundle.js': ['browserify'],
 			'packages/metal*/test/**/*.js': ['browserify']
 		},
 
diff --git a/packages/metal-soy-bundle/README.md b/packages/metal-soy-bundle/README.md
index 85dd8078..13182ddf 100644
--- a/packages/metal-soy-bundle/README.md
+++ b/packages/metal-soy-bundle/README.md
@@ -4,3 +4,15 @@ metal-soy-bundle
 A bundle containing all the closure dependencies required by soy files compiled to incremental-dom.
 
 Note that this bundle was built by hand, and some features were deliberately removed to make the resulting bundle smaller, like escaping (which shouldn't be necessary for incremental dom anyway) and bidi directives (which will be added back soon).
+
+## Build Process
+
+There are two steps to generating the consumable `lib/bundle.js` file. The entire process is triggered by the `npm prepublish` script.
+
+### Concatentation
+
+The `gulp build` task first concatenates the files found in the `src/closure-library` and `src/closure-templates` directories into the `build/bundle.js` file.
+
+### Transpilation
+
+Once the source files have been concatenated, the generated `build/bundle.js` file is transpiled by the `npm compile` script and placed in the `lib` directory at `lib/bundle.js`. This file is the entry point for the `metal-soy-bundle` package.
diff --git a/packages/metal-soy-bundle/gulpfile.js b/packages/metal-soy-bundle/gulpfile.js
index c48d87c3..dd7cd071 100644
--- a/packages/metal-soy-bundle/gulpfile.js
+++ b/packages/metal-soy-bundle/gulpfile.js
@@ -23,7 +23,13 @@ gulp.task('build', function() {
   return gulp.src(dependencies)
     .pipe(concat('bundle.js'))
     .pipe(replace('var goog = goog || {};', 'var goog = this.goog || {};'))
-    .pipe(header('import \'metal-incremental-dom\';\n\n(function() {\nthis.CLOSURE_NO_DEPS = true;\nthis.goog = this.goog || {};\n\n'))
+    .pipe(header('import \'metal-incremental-dom\';\n\n(function() {\nthis.CLOSURE_NO_DEPS = true;\nthis.goog = this.goog || {};\n\n' +
+      'if (this.__METAL_SOY_BUNDLE_LOADED__) {\n' +
+      '  console.warn(\'Warning: metal-soy-bundle has already been loaded. Dedupe bundle to remove this warning.\');\n' +
+      '  return;\n' +
+      '}\n' +
+      'this.__METAL_SOY_BUNDLE_LOADED__ = true;\n\n'
+    ))
     .pipe(footer('\n\ngoog.loadModule(function() {\n' +
       '  goog.module(\'incrementaldom\');\n' +
       '  return IncrementalDOM;\n' +
diff --git a/packages/metal-soy-bundle/test/bundle.js b/packages/metal-soy-bundle/test/bundle.js
new file mode 100644
index 00000000..24eabd80
--- /dev/null
+++ b/packages/metal-soy-bundle/test/bundle.js
@@ -0,0 +1,32 @@
+describe('metal-soy-bundle', function() {
+	before(function() {
+		sinon.stub(console, 'warn');
+	});
+
+	after(function() {
+		console.warn.restore();
+	});
+
+	it('should show warning instead of erroring when loading bundle twice', function(done) {
+		assert(window.__METAL_SOY_BUNDLE_LOADED__);
+		assert.equal(console.warn.callCount, 0);
+
+		loadBundle(function() {
+			assert.equal(console.warn.callCount, 1);
+			assert(console.warn.calledWith('Warning: metal-soy-bundle has already been loaded. Dedupe bundle to remove this warning.'));
+
+			done();
+		});
+	});
+});
+
+function loadBundle(done) {
+	var script = document.createElement('script');
+
+	script.crossOrigin = 'anonymous';
+	script.onload = done;
+	script.src = '/base/packages/metal-soy-bundle/build/bundle.js';
+	script.type = 'text/javascript';
+
+	document.body.appendChild(script);
+}