diff --git a/src/generators/dom/index.js b/src/generators/dom/index.js
index 32b9ec793d..5bfb472e86 100644
--- a/src/generators/dom/index.js
+++ b/src/generators/dom/index.js
@@ -393,18 +393,17 @@ export default function dom ( parsed, source, options ) {
 
 	const sharedPath = options.shared === true ? 'svelte/shared.js' : options.shared;
 
-	if ( sharedPath ) {
-		const base = templateProperties.methods ? `{}, ${generator.alias( 'template' )}.methods` : `{}`;
-		builders.main.addBlock( `${name}.prototype = ${generator.helper( 'assign' )}( ${base}, ${generator.helper( 'proto' )} );` );
-	} else {
-		if ( templateProperties.methods ) {
-			builders.main.addBlock( `${name}.prototype = ${generator.alias( 'template' )}.methods;` );
-		}
+	const prototypeBase = `${name}.prototype` + ( templateProperties.methods ? `, ${generator.alias( 'template' )}.methods` : '' );
+	const proto = sharedPath ? `${generator.helper( 'proto' )} ` : deindent`
+		{
+			${
+				[ 'get', 'fire', 'observe', 'on', 'set', '_flush' ]
+					.map( n => `${n}: ${generator.helper( n )}` )
+					.join( ',\n' )
+			}
+		}`;
 
-		[ 'get', 'fire', 'observe', 'on', 'set', '_flush' ].forEach( methodName => {
-			builders.main.addLine( `${name}.prototype.${methodName} = ${generator.helper( methodName )};` );
-		});
-	}
+	builders.main.addBlock( `${generator.helper( 'assign' )}( ${prototypeBase}, ${proto});` );
 
 	// TODO deprecate component.teardown()
 	builders.main.addBlock( deindent`
diff --git a/src/index.js b/src/index.js
index 7de2a9b821..b7f158a84f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,10 +2,11 @@ import parse from './parse/index.js';
 import validate from './validate/index.js';
 import generate from './generators/dom/index.js';
 import generateSSR from './generators/server-side-rendering/index.js';
+import { assign } from './shared/index.js';
 import { version } from '../package.json';
 
 function normalizeOptions ( options ) {
-	return Object.assign( {
+	return assign( {
 		generate: 'dom',
 
 		// a filename is necessary for sourcemap generation
diff --git a/test/generator/index.js b/test/generator/index.js
index 8ee4280828..6ca442623b 100644
--- a/test/generator/index.js
+++ b/test/generator/index.js
@@ -141,8 +141,12 @@ describe( 'generate', () => {
 						component.destroy();
 						assert.equal( target.innerHTML, '' );
 					}
+
+					Object.assign = Object_assign;
 				})
 				.catch( err => {
+					Object.assign = Object_assign;
+
 					if ( config.error && !unintendedError ) {
 						config.error( assert, err );
 					}
@@ -151,9 +155,6 @@ describe( 'generate', () => {
 						if ( !config.show ) console.log( addLineNumbers( code ) ); // eslint-disable-line no-console
 						throw err;
 					}
-				})
-				.then( () => {
-					Object.assign = Object_assign;
 				});
 		});
 	}