diff --git a/src/Bundle.js b/src/Bundle.js
index 692ab08..d98db39 100644
--- a/src/Bundle.js
+++ b/src/Bundle.js
@@ -377,6 +377,10 @@ export default class Bundle {
 			}
 		});
 
+		if ( !magicString.toString().trim() && this.entryModule.getExports().length === 0 ) {
+			this.onwarn( 'Generated an empty bundle' );
+		}
+
 		timeEnd( 'render modules' );
 
 		let intro = [ options.intro ]
diff --git a/test/function/assign-namespace-to-var/_config.js b/test/function/assign-namespace-to-var/_config.js
index ce0a100..2eb7e9c 100644
--- a/test/function/assign-namespace-to-var/_config.js
+++ b/test/function/assign-namespace-to-var/_config.js
@@ -1,3 +1,10 @@
+const assert = require( 'assert' );
+
 module.exports = {
-	description: 'allows a namespace to be assigned to a variable'
+	description: 'allows a namespace to be assigned to a variable',
+	warnings: warnings => {
+		assert.deepEqual( warnings, [
+			'Generated an empty bundle'
+		]);
+	}
 };
diff --git a/test/function/consistent-renaming/main.js b/test/function/consistent-renaming/main.js
index e4209a5..fd52eba 100644
--- a/test/function/consistent-renaming/main.js
+++ b/test/function/consistent-renaming/main.js
@@ -1,3 +1,7 @@
 import { one as oneRenamed } from './one';
 import { two } from './two';
-import { three as threeRenamed } from './three';
\ No newline at end of file
+import { three as threeRenamed } from './three';
+
+assert.equal( oneRenamed, 1 );
+assert.equal( two, 2 );
+assert.equal( threeRenamed, 3 );
diff --git a/test/function/cycles-pathological-3/_config.js b/test/function/cycles-pathological-3/_config.js
deleted file mode 100644
index 155e2f6..0000000
--- a/test/function/cycles-pathological-3/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-module.exports = {
-	description: 'resolves more pathological cyclical dependencies gracefully'
-};
diff --git a/test/function/cycles-pathological-3/a.js b/test/function/cycles-pathological-3/a.js
deleted file mode 100644
index c77b86b..0000000
--- a/test/function/cycles-pathological-3/a.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import * as x from "./x.a.js";
-x.b();
-x.c();
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/b.js b/test/function/cycles-pathological-3/b.js
deleted file mode 100644
index b93201c..0000000
--- a/test/function/cycles-pathological-3/b.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import * as x from "./x.b.js";
-
-export function b() {}
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/c.js b/test/function/cycles-pathological-3/c.js
deleted file mode 100644
index 60a9826..0000000
--- a/test/function/cycles-pathological-3/c.js
+++ /dev/null
@@ -1,3 +0,0 @@
-import * as x from "./x.c.js";
-
-export function c() {}
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/main.js b/test/function/cycles-pathological-3/main.js
deleted file mode 100644
index 1580611..0000000
--- a/test/function/cycles-pathological-3/main.js
+++ /dev/null
@@ -1 +0,0 @@
-import './a.js';
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/x.a.js b/test/function/cycles-pathological-3/x.a.js
deleted file mode 100644
index e73df11..0000000
--- a/test/function/cycles-pathological-3/x.a.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export * from "./b.js";
-export * from "./c.js";
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/x.b.js b/test/function/cycles-pathological-3/x.b.js
deleted file mode 100644
index c3e2ed3..0000000
--- a/test/function/cycles-pathological-3/x.b.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export * from "./a.js";
-export * from "./c.js";
\ No newline at end of file
diff --git a/test/function/cycles-pathological-3/x.c.js b/test/function/cycles-pathological-3/x.c.js
deleted file mode 100644
index 2f49591..0000000
--- a/test/function/cycles-pathological-3/x.c.js
+++ /dev/null
@@ -1,2 +0,0 @@
-export * from "./a.js";
-export * from "./b.js";
\ No newline at end of file
diff --git a/test/function/empty-exports/_config.js b/test/function/empty-exports/_config.js
index 65b2185..8030197 100644
--- a/test/function/empty-exports/_config.js
+++ b/test/function/empty-exports/_config.js
@@ -1,17 +1,12 @@
-var assert = require( 'assert' );
-
-var warned = false;
+const assert = require( 'assert' );
+const path = require( 'path' );
 
 module.exports = {
 	description: 'warns on export {}, but does not fail',
-	options: {
-		onwarn: function ( msg ) {
-			warned = true;
-			assert.ok( /main\.js has an empty export declaration/.test( msg ) );
-		}
-	},
-	exports: function ( exports ) {
-		assert.equal( Object.keys( exports ).length, 0 );
-		assert.ok( warned, 'did not warn' );
+	warnings: warnings => {
+		assert.deepEqual( warnings, [
+			`Module ${path.resolve( __dirname, 'main.js' )} has an empty export declaration`,
+			'Generated an empty bundle'
+		]);
 	}
 };
diff --git a/test/function/handles-multiple-declarations/_config.js b/test/function/handles-multiple-declarations/_config.js
deleted file mode 100644
index 94022ee..0000000
--- a/test/function/handles-multiple-declarations/_config.js
+++ /dev/null
@@ -1,3 +0,0 @@
-module.exports = {
-	description: 'handles multiple declaration blocks with multiple declarations (#105)'
-};
diff --git a/test/function/handles-multiple-declarations/main.js b/test/function/handles-multiple-declarations/main.js
deleted file mode 100644
index a8af4cd..0000000
--- a/test/function/handles-multiple-declarations/main.js
+++ /dev/null
@@ -1,2 +0,0 @@
-var a, b;
-var c, d;
diff --git a/test/function/module-tree/_config.js b/test/function/module-tree/_config.js
index 553ab2b..9662844 100644
--- a/test/function/module-tree/_config.js
+++ b/test/function/module-tree/_config.js
@@ -33,5 +33,10 @@ module.exports = {
 				dependencies: [ 'foo.js', 'bar.js' ]
 			}
 		]);
+	},
+	warnings: warnings => {
+		assert.deepEqual( warnings, [
+			'Generated an empty bundle'
+		]);
 	}
 };
diff --git a/test/function/warn-on-empty-bundle/_config.js b/test/function/warn-on-empty-bundle/_config.js
new file mode 100644
index 0000000..2e599ad
--- /dev/null
+++ b/test/function/warn-on-empty-bundle/_config.js
@@ -0,0 +1,10 @@
+const assert = require( 'assert' );
+
+module.exports = {
+	description: 'warns if empty bundle is generated  (#444)',
+	warnings: warnings => {
+		assert.deepEqual( warnings, [
+			'Generated an empty bundle'
+		]);
+	}
+};
diff --git a/test/function/warn-on-empty-bundle/main.js b/test/function/warn-on-empty-bundle/main.js
new file mode 100644
index 0000000..235183b
--- /dev/null
+++ b/test/function/warn-on-empty-bundle/main.js
@@ -0,0 +1,2 @@
+function noop () {}
+noop();