diff --git a/package.json b/package.json
index b5f55c2..fcc43da 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
   "dependencies": {
     "acorn": "^1.1.0",
     "chalk": "^1.0.0",
-    "magic-string": "^0.6.2",
+    "magic-string": "^0.6.4",
     "minimist": "^1.1.1",
     "sander": "^0.3.3",
     "source-map-support": "^0.3.1"
diff --git a/src/Bundle.js b/src/Bundle.js
index 4ed55a0..3bf0138 100644
--- a/src/Bundle.js
+++ b/src/Bundle.js
@@ -13,15 +13,6 @@ import getExportMode from './utils/getExportMode';
 import getIndentString from './utils/getIndentString';
 import { unixizePath } from './utils/normalizePlatform.js';
 
-function isEmptyExportedVarDeclaration ( node, module, allBundleExports, es6 ) {
-	if ( node.type !== 'VariableDeclaration' || node.declarations[0].init ) return false;
-
-	const name = node.declarations[0].id.name;
-	const canonicalName = module.getCanonicalName( name, es6 );
-
-	return canonicalName in allBundleExports;
-}
-
 export default class Bundle {
 	constructor ( options ) {
 		this.entry = options.entry;
@@ -90,7 +81,7 @@ export default class Bundle {
 				return this.markAllModifierStatements();
 			})
 			.then( () => {
-				this.statements = this.sort();
+				this.orderedModules = this.sort();
 			});
 	}
 
@@ -115,34 +106,35 @@ export default class Bundle {
 		});
 
 		// Discover conflicts (i.e. two statements in separate modules both define `foo`)
-		this.statements.forEach( statement => {
-			const module = statement.module;
-			const names = keys( statement.defines );
+		this.orderedModules.forEach( module => {
+			module.statements.forEach( statement => {
+				const names = keys( statement.defines );
 
-			// with default exports that are expressions (`export default 42`),
-			// we need to ensure that the name chosen for the expression does
-			// not conflict
-			if ( statement.node.type === 'ExportDefaultDeclaration' ) {
-				const name = module.getCanonicalName( 'default', es6 );
+				// with default exports that are expressions (`export default 42`),
+				// we need to ensure that the name chosen for the expression does
+				// not conflict
+				if ( statement.node.type === 'ExportDefaultDeclaration' ) {
+					const name = module.getCanonicalName( 'default', es6 );
 
-				const isProxy = statement.node.declaration && statement.node.declaration.type === 'Identifier';
-				const shouldDeconflict = !isProxy || ( module.getCanonicalName( statement.node.declaration.name, es6 ) !== name );
+					const isProxy = statement.node.declaration && statement.node.declaration.type === 'Identifier';
+					const shouldDeconflict = !isProxy || ( module.getCanonicalName( statement.node.declaration.name, es6 ) !== name );
 
-				if ( shouldDeconflict && !~names.indexOf( name ) ) {
-					names.push( name );
+					if ( shouldDeconflict && !~names.indexOf( name ) ) {
+						names.push( name );
+					}
 				}
-			}
 
-			names.forEach( name => {
-				if ( definers[ name ] ) {
-					conflicts[ name ] = true;
-				} else {
-					definers[ name ] = [];
-				}
+				names.forEach( name => {
+					if ( definers[ name ] ) {
+						conflicts[ name ] = true;
+					} else {
+						definers[ name ] = [];
+					}
 
-				// TODO in good js, there shouldn't be duplicate definitions
-				// per module... but some people write bad js
-				definers[ name ].push( module );
+					// TODO in good js, there shouldn't be duplicate definitions
+					// per module... but some people write bad js
+					definers[ name ].push( module );
+				});
 			});
 		});
 
@@ -213,9 +205,58 @@ export default class Bundle {
 			});
 	}
 
-	generate ( options = {} ) {
-		let magicString = new MagicString.Bundle({ separator: '' });
+	markAllModifierStatements () {
+		let settled = true;
+		let promises = [];
+
+		this.modules.forEach( module => {
+			module.statements.forEach( statement => {
+				if ( statement.isIncluded ) return;
+
+				keys( statement.modifies ).forEach( name => {
+					const definingStatement = module.definitions[ name ];
+					const exportDeclaration = module.exports[ name ] || (
+						module.exports.default && module.exports.default.identifier === name && module.exports.default
+					);
+
+					const shouldMark = ( definingStatement && definingStatement.isIncluded ) ||
+					                   ( exportDeclaration && exportDeclaration.isUsed );
+
+					if ( shouldMark ) {
+						settled = false;
+						promises.push( statement.mark() );
+						return;
+					}
+
+					// special case - https://github.com/rollup/rollup/pull/40
+					const importDeclaration = module.imports[ name ];
+					if ( !importDeclaration ) return;
+
+					const promise = Promise.resolve( importDeclaration.module || this.fetchModule( importDeclaration.source, module.id ) )
+						.then( module => {
+							importDeclaration.module = module;
+							const exportDeclaration = module.exports[ importDeclaration.name ];
+							// TODO things like `export default a + b` don't apply here... right?
+							return module.findDefiningStatement( exportDeclaration.localName );
+						})
+						.then( definingStatement => {
+							if ( !definingStatement ) return;
+
+							settled = false;
+							return statement.mark();
+						});
+
+					promises.push( promise );
+				});
+			});
+		});
 
+		return Promise.all( promises ).then( () => {
+			if ( !settled ) return this.markAllModifierStatements();
+		});
+	}
+
+	render ( options = {} ) {
 		const format = options.format || 'es6';
 		this.deconflict( format === 'es6' );
 
@@ -256,113 +297,14 @@ export default class Bundle {
 		this.toExport = keys( this.entryModule.exports )
 			.filter( key => !this.varExports[ key ] );
 
-		// Apply new names and add to the output bundle
-		let previousModule = null;
-		let previousIndex = -1;
-		let previousMargin = 0;
 
-		this.statements.forEach( statement => {
-			// skip `export { foo, bar, baz }`
-			if ( statement.node.type === 'ExportNamedDeclaration' ) {
-				// skip `export { foo, bar, baz }`
-				if ( statement.node.specifiers.length ) return;
+		let magicString = new MagicString.Bundle({ separator: '\n\n' });
 
-				// skip `export var foo;` if foo is exported
-				if ( isEmptyExportedVarDeclaration( statement.node.declaration, statement.module, allBundleExports, format === 'es6' ) ) return;
+		this.orderedModules.forEach( module => {
+			const source = module.render( allBundleExports, format );
+			if ( source.toString().length ) {
+				magicString.addSource( source );
 			}
-
-			// skip empty var declarations for exported bindings
-			// (otherwise we're left with `exports.foo;`, which is useless)
-			if ( isEmptyExportedVarDeclaration( statement.node, statement.module, allBundleExports, format === 'es6' ) ) return;
-
-			let replacements = blank();
-			let bundleExports = blank();
-
-			keys( statement.dependsOn )
-				.concat( keys( statement.defines ) )
-				.forEach( name => {
-					const canonicalName = statement.module.getCanonicalName( name, format === 'es6' );
-
-					if ( allBundleExports[ canonicalName ] ) {
-						bundleExports[ name ] = replacements[ name ] = allBundleExports[ canonicalName ];
-					} else if ( name !== canonicalName ) {
-						replacements[ name ] = canonicalName;
-					}
-				});
-
-			const source = statement.replaceIdentifiers( replacements, bundleExports );
-
-			// modify exports as necessary
-			if ( statement.isExportDeclaration ) {
-				// remove `export` from `export var foo = 42`
-				if ( statement.node.type === 'ExportNamedDeclaration' && statement.node.declaration.type === 'VariableDeclaration' ) {
-					source.remove( statement.node.start, statement.node.declaration.start );
-				}
-
-				// remove `export` from `export class Foo {...}` or `export default Foo`
-				// TODO default exports need different treatment
-				else if ( statement.node.declaration.id ) {
-					source.remove( statement.node.start, statement.node.declaration.start );
-				}
-
-				else if ( statement.node.type === 'ExportDefaultDeclaration' ) {
-					const module = statement.module;
-					const canonicalName = module.getCanonicalName( 'default', format === 'es6' );
-
-					if ( statement.node.declaration.type === 'Identifier' && canonicalName === module.getCanonicalName( statement.node.declaration.name, format === 'es6' ) ) {
-						return;
-					}
-
-					// anonymous functions should be converted into declarations
-					if ( statement.node.declaration.type === 'FunctionExpression' ) {
-						source.overwrite( statement.node.start, statement.node.declaration.start + 8, `function ${canonicalName}` );
-					} else {
-						source.overwrite( statement.node.start, statement.node.declaration.start, `var ${canonicalName} = ` );
-					}
-				}
-
-				else {
-					throw new Error( 'Unhandled export' );
-				}
-			}
-
-			// ensure there is always a newline between statements, and add
-			// additional newlines as necessary to reflect original source
-			const minSeparation = ( previousModule !== statement.module ) || ( statement.index !== previousIndex + 1 ) ? 3 : 2;
-			const margin = Math.max( minSeparation, statement.margin[0], previousMargin );
-			let newLines = new Array( margin ).join( '\n' );
-
-			// add leading comments
-			if ( statement.leadingComments.length ) {
-				const commentBlock = newLines + statement.leadingComments.map( ({ separator, comment }) => {
-					return separator + ( comment.block ?
-						`/*${comment.text}*/` :
-						`//${comment.text}` );
-				}).join( '' );
-
-				magicString.addSource( new MagicString( commentBlock ) );
-				newLines = new Array( statement.margin[0] ).join( '\n' ); // TODO handle gaps between comment block and statement
-			}
-
-			// add the statement itself
-			magicString.addSource({
-				content: source,
-				separator: newLines
-			});
-
-			// add trailing comments
-			const comment = statement.trailingComment;
-			if ( comment ) {
-				const commentBlock = comment.block ?
-					` /*${comment.text}*/` :
-					` //${comment.text}`;
-
-				magicString.append( commentBlock );
-			}
-
-			previousMargin = statement.margin[1];
-			previousModule = statement.module;
-			previousIndex  = statement.index;
 		});
 
 		// prepend bundle with internal namespaces
@@ -408,57 +350,6 @@ export default class Bundle {
 		return { code, map };
 	}
 
-	markAllModifierStatements () {
-		let settled = true;
-		let promises = [];
-
-		this.modules.forEach( module => {
-			module.statements.forEach( statement => {
-				if ( statement.isIncluded ) return;
-
-				keys( statement.modifies ).forEach( name => {
-					const definingStatement = module.definitions[ name ];
-					const exportDeclaration = module.exports[ name ] || (
-						module.exports.default && module.exports.default.identifier === name && module.exports.default
-					);
-
-					const shouldMark = ( definingStatement && definingStatement.isIncluded ) ||
-					                   ( exportDeclaration && exportDeclaration.isUsed );
-
-					if ( shouldMark ) {
-						settled = false;
-						promises.push( statement.mark() );
-						return;
-					}
-
-					// special case - https://github.com/rollup/rollup/pull/40
-					const importDeclaration = module.imports[ name ];
-					if ( !importDeclaration ) return;
-
-					const promise = Promise.resolve( importDeclaration.module || this.fetchModule( importDeclaration.source, module.id ) )
-						.then( module => {
-							importDeclaration.module = module;
-							const exportDeclaration = module.exports[ importDeclaration.name ];
-							// TODO things like `export default a + b` don't apply here... right?
-							return module.findDefiningStatement( exportDeclaration.localName );
-						})
-						.then( definingStatement => {
-							if ( !definingStatement ) return;
-
-							settled = false;
-							return statement.mark();
-						});
-
-					promises.push( promise );
-				});
-			});
-		});
-
-		return Promise.all( promises ).then( () => {
-			if ( !settled ) return this.markAllModifierStatements();
-		});
-	}
-
 	sort () {
 		let seen = {};
 		let ordered = [];
@@ -540,14 +431,6 @@ export default class Bundle {
 			});
 		}
 
-		let statements = [];
-
-		ordered.forEach( module => {
-			module.statements.forEach( statement => {
-				if ( statement.isIncluded ) statements.push( statement );
-			});
-		});
-
-		return statements;
+		return ordered;
 	}
 }
diff --git a/src/Module.js b/src/Module.js
index a26e340..3cf9b8a 100644
--- a/src/Module.js
+++ b/src/Module.js
@@ -4,10 +4,8 @@ import { parse } from 'acorn';
 import MagicString from 'magic-string';
 import Statement from './Statement';
 import walk from './ast/walk';
-import analyse from './ast/analyse';
 import { blank, keys } from './utils/object';
 import { first, sequence } from './utils/promise';
-import { isImportDeclaration, isExportDeclaration } from './utils/map-helpers';
 import getLocation from './utils/getLocation';
 import makeLegalIdentifier from './utils/makeLegalIdentifier';
 
@@ -21,6 +19,15 @@ function deconflict ( name, names ) {
 	return name;
 }
 
+function isEmptyExportedVarDeclaration ( node, module, allBundleExports, es6 ) {
+	if ( node.type !== 'VariableDeclaration' || node.declarations[0].init ) return false;
+
+	const name = node.declarations[0].id.name;
+	const canonicalName = module.getCanonicalName( name, es6 );
+
+	return canonicalName in allBundleExports;
+}
+
 export default class Module {
 	constructor ({ id, source, bundle }) {
 		this.source = source;
@@ -169,14 +176,12 @@ export default class Module {
 	analyse () {
 		// discover this module's imports and exports
 		this.statements.forEach( statement => {
-			if ( isImportDeclaration( statement ) ) this.addImport( statement );
-			else if ( isExportDeclaration( statement ) ) this.addExport( statement );
-		});
+			if ( statement.isImportDeclaration ) this.addImport( statement );
+			else if ( statement.isExportDeclaration ) this.addExport( statement );
 
-		analyse( this.magicString, this );
+			statement.analyse();
 
-		// consolidate names that are defined/modified in this module
-		this.statements.forEach( statement => {
+			// consolidate names that are defined/modified in this module
 			keys( statement.defines ).forEach( name => {
 				this.definitions[ name ] = statement;
 			});
@@ -530,37 +535,60 @@ export default class Module {
 		});
 
 		let statements = [];
+		let lastChar = 0;
+		let commentIndex = 0;
 
-		ast.body.map( node => {
+		ast.body.forEach( node => {
 			// special case - top-level var declarations with multiple declarators
 			// should be split up. Otherwise, we may end up including code we
 			// don't need, just because an unwanted declarator is included
 			if ( node.type === 'VariableDeclaration' && node.declarations.length > 1 ) {
-				node.declarations.forEach( declarator => {
-					const magicString = this.magicString.snip( declarator.start, declarator.end ).trim();
-					magicString.prepend( `${node.kind} ` ).append( ';' );
+				// remove the leading var/let/const
+				this.magicString.remove( node.start, node.declarations[0].start );
+
+				node.declarations.forEach( ( declarator, i ) => {
+					const { start, end } = declarator;
 
 					const syntheticNode = {
 						type: 'VariableDeclaration',
 						kind: node.kind,
-						start: node.start,
-						end: node.end,
-						declarations: [ declarator ]
+						start,
+						end,
+						declarations: [ declarator ],
+						isSynthetic: true
 					};
 
-					const statement = new Statement( syntheticNode, magicString, this, statements.length );
+					const statement = new Statement( syntheticNode, this, start, end );
 					statements.push( statement );
 				});
+
+				lastChar = node.end; // TODO account for trailing line comment
 			}
 
 			else {
-				const magicString = this.magicString.snip( node.start, node.end ).trim();
-				const statement = new Statement( node, magicString, this, statements.length );
-
+				let comment;
+				do {
+					comment = this.comments[ commentIndex ];
+					if ( !comment ) break;
+					if ( comment.start > node.start ) break;
+					commentIndex += 1;
+				} while ( comment.end < lastChar );
+
+				const start = comment ? Math.min( comment.start, node.start ) : node.start;
+				const end = node.end; // TODO account for trailing line comment
+
+				const statement = new Statement( node, this, start, end );
 				statements.push( statement );
+
+				lastChar = end;
 			}
 		});
 
+		statements.forEach( ( statement, i ) => {
+			const nextStatement = statements[ i + 1 ];
+			statement.next = nextStatement ? nextStatement.start : statement.end;
+		});
+
 		return statements;
 	}
 
@@ -569,6 +597,102 @@ export default class Module {
 		this.canonicalNames[ name ] = this.canonicalNames[ name + '-es6' ] = replacement;
 	}
 
+	render ( allBundleExports, format ) {
+		let magicString = this.magicString.clone();
+
+		let previousIndex = -1;
+		let previousMargin = 0;
+
+		this.statements.forEach( ( statement, i ) => {
+			if ( !statement.isIncluded ) {
+				magicString.remove( statement.start, statement.next );
+				return;
+			}
+
+			// skip `export { foo, bar, baz }`
+			if ( statement.node.type === 'ExportNamedDeclaration' ) {
+				// skip `export { foo, bar, baz }`
+				if ( statement.node.specifiers.length ) {
+					magicString.remove( statement.start, statement.next );
+					return;
+				};
+
+				// skip `export var foo;` if foo is exported
+				if ( isEmptyExportedVarDeclaration( statement.node.declaration, statement.module, allBundleExports, format === 'es6' ) ) {
+					magicString.remove( statement.start, statement.next );
+					return;
+				}
+			}
+
+			// skip empty var declarations for exported bindings
+			// (otherwise we're left with `exports.foo;`, which is useless)
+			if ( isEmptyExportedVarDeclaration( statement.node, statement.module, allBundleExports, format === 'es6' ) ) {
+				magicString.remove( statement.start, statement.next );
+				return;
+			}
+
+			// split up/remove var declarations as necessary
+			if ( statement.node.isSynthetic ) {
+				magicString.insert( statement.start, `${statement.node.kind} ` );
+				magicString.overwrite( statement.end, statement.next, ';\n' ); // TODO account for trailing newlines
+			}
+
+			let replacements = blank();
+			let bundleExports = blank();
+
+			keys( statement.dependsOn )
+				.concat( keys( statement.defines ) )
+				.forEach( name => {
+					const canonicalName = statement.module.getCanonicalName( name, format === 'es6' );
+
+					if ( allBundleExports[ canonicalName ] ) {
+						bundleExports[ name ] = replacements[ name ] = allBundleExports[ canonicalName ];
+					} else if ( name !== canonicalName ) {
+						replacements[ name ] = canonicalName;
+					}
+				});
+
+			statement.replaceIdentifiers( magicString, replacements, bundleExports );
+
+			// modify exports as necessary
+			if ( statement.isExportDeclaration ) {
+				// remove `export` from `export var foo = 42`
+				if ( statement.node.type === 'ExportNamedDeclaration' && statement.node.declaration.type === 'VariableDeclaration' ) {
+					magicString.remove( statement.node.start, statement.node.declaration.start );
+				}
+
+				// remove `export` from `export class Foo {...}` or `export default Foo`
+				// TODO default exports need different treatment
+				else if ( statement.node.declaration.id ) {
+					magicString.remove( statement.node.start, statement.node.declaration.start );
+				}
+
+				else if ( statement.node.type === 'ExportDefaultDeclaration' ) {
+					const module = statement.module;
+					const canonicalName = module.getCanonicalName( 'default', format === 'es6' );
+
+					if ( statement.node.declaration.type === 'Identifier' && canonicalName === module.getCanonicalName( statement.node.declaration.name, format === 'es6' ) ) {
+						magicString.remove( statement.start, statement.next );
+						return;
+					}
+
+					// anonymous functions should be converted into declarations
+					if ( statement.node.declaration.type === 'FunctionExpression' ) {
+						magicString.overwrite( statement.node.start, statement.node.declaration.start + 8, `function ${canonicalName}` );
+					} else {
+						magicString.overwrite( statement.node.start, statement.node.declaration.start, `var ${canonicalName} = ` );
+					}
+				}
+
+				else {
+					throw new Error( 'Unhandled export' );
+				}
+			}
+		});
+
+		return magicString.trim();
+	}
+
 	suggestName ( defaultOrBatch, suggestion ) {
 		// deconflict anonymous default exports with this module's definitions
 		const shouldDeconflict = this.exports.default && this.exports.default.isAnonymous;
diff --git a/src/Statement.js b/src/Statement.js
index 7cfbebf..43b6bf7 100644
--- a/src/Statement.js
+++ b/src/Statement.js
@@ -9,12 +9,12 @@ function isIife ( node, parent ) {
 }
 
 export default class Statement {
-	constructor ( node, magicString, module, index ) {
+	constructor ( node, module, start, end ) {
 		this.node = node;
 		this.module = module;
-		this.magicString = magicString;
-		this.index = index;
-		this.id = module.id + '#' + index;
+		this.start = start;
+		this.end = end;
+		this.next = null; // filled in later
 
 		this.scope = new Scope();
 		this.defines = blank();
@@ -24,30 +24,19 @@ export default class Statement {
 
 		this.isIncluded = false;
 
-		this.leadingComments = [];
-		this.trailingComment = null;
-		this.margin = [ 0, 0 ];
-
-		// some facts about this statement...
 		this.isImportDeclaration = node.type === 'ImportDeclaration';
 		this.isExportDeclaration = /^Export/.test( node.type );
-		this.isExportAllDeclaration = /^ExportAll/.test( node.type );
 	}
 
 	analyse () {
 		if ( this.isImportDeclaration ) return; // nothing to analyse
 
-		const statement = this; // TODO use arrow functions instead
-		const magicString = this.magicString;
-
 		let scope = this.scope;
 
 		walk( this.node, {
 			enter ( node, parent ) {
 				let newScope;
 
-				magicString.addSourcemapLocation( node.start );
-
 				switch ( node.type ) {
 					case 'FunctionExpression':
 					case 'FunctionDeclaration':
@@ -146,7 +135,7 @@ export default class Statement {
 		}
 
 		keys( scope.declarations ).forEach( name => {
-			statement.defines[ name ] = true;
+			this.defines[ name ] = true;
 		});
 	}
 
@@ -247,8 +236,7 @@ export default class Statement {
 		});
 	}
 
-	replaceIdentifiers ( names, bundleExports ) {
-		const magicString = this.magicString.clone();
+	replaceIdentifiers ( magicString, names, bundleExports ) {
 		const replacementStack = [ names ];
 		const nameList = keys( names );
 
@@ -292,11 +280,13 @@ export default class Statement {
 								.map( name => `\n${bundleExports[name]} = ${name};` )
 								.join( '' );
 
-							// TODO clean this up
-							try {
-								magicString.insert( node.end, exportInitialisers );
-							} catch ( err ) {
-								magicString.append( exportInitialisers );
+							if ( exportInitialisers ) {
+								// TODO clean this up
+								try {
+									magicString.insert( node.end, exportInitialisers );
+								} catch ( err ) {
+									magicString.append( exportInitialisers );
+								}
 							}
 						}
 					}
diff --git a/src/ast/analyse.js b/src/ast/analyse.js
deleted file mode 100644
index 21b5f4c..0000000
--- a/src/ast/analyse.js
+++ /dev/null
@@ -1,66 +0,0 @@
-export default function analyse ( magicString, module ) {
-	// first we need to generate comprehensive scope info
-	let previousStatement = null;
-	let commentIndex = 0;
-
-	module.statements.forEach( statement => {
-		const node = statement.node;
-
-		let trailing = !!previousStatement;
-		let previousComment;
-
-		// TODO surely this can be neater
-		// attach leading comment
-		do {
-			let comment = module.comments[ commentIndex ];
-
-			// prevent comments inside the previous statement being
-			// appended to it
-			if ( previousStatement ) {
-				while ( comment && comment.start < previousStatement.node.end ) {
-					commentIndex += 1;
-					comment = module.comments[ commentIndex ];
-				}
-			}
-
-			if ( !comment || ( comment.end > node.start ) ) break;
-
-			// attach any trailing comment to the previous statement
-			if ( trailing && !/\n/.test( module.source.slice( previousStatement.node.end, comment.start ) ) ) {
-				previousStatement.trailingComment = comment;
-			}
-
-			// then attach leading comments to this statement
-			else {
-				statement.leadingComments.push({
-					separator: previousComment ? magicString.slice( previousComment.end, comment.start ) : '\n',
-					comment
-				});
-
-				previousComment = comment;
-			}
-
-			commentIndex += 1;
-			trailing = false;
-		} while ( module.comments[ commentIndex ] );
-
-		// determine margin
-		const previousEnd = previousComment ?
-			previousComment.end :
-			previousStatement ?
-				( previousStatement.trailingComment || previousStatement.node ).end :
-				0;
-
-		//const start = ( statement.leadingComments[0] || node ).start;
-
-		const gap = magicString.original.slice( previousEnd, node.start );
-		const margin = gap.split( '\n' ).length;
-
-		if ( previousStatement ) previousStatement.margin[1] = margin;
-		statement.margin[0] = margin;
-
-		statement.analyse();
-
-		previousStatement = statement;
-	});
-}
diff --git a/src/rollup.js b/src/rollup.js
index 0b8a652..846c8f2 100644
--- a/src/rollup.js
+++ b/src/rollup.js
@@ -14,14 +14,14 @@ export function rollup ( options ) {
 
 	return bundle.build().then( () => {
 		return {
-			generate: options => bundle.generate( options ),
+			generate: options => bundle.render( options ),
 			write: options => {
 				if ( !options || !options.dest ) {
 					throw new Error( 'You must supply options.dest to bundle.write' );
 				}
 
 				const dest = options.dest;
-				let { code, map } = bundle.generate( options );
+				let { code, map } = bundle.render( options );
 
 				let promises = [];
 
diff --git a/src/utils/map-helpers.js b/src/utils/map-helpers.js
index 9576535..49e0942 100644
--- a/src/utils/map-helpers.js
+++ b/src/utils/map-helpers.js
@@ -9,11 +9,3 @@ export function quoteId ( x ) {
 export function req ( x ) {
 	return `require('${x.id}')`;
 }
-
-export function isImportDeclaration ( statement ) {
-	return statement.isImportDeclaration;
-}
-
-export function isExportDeclaration ( statement ) {
-	return statement.isExportDeclaration;
-}
diff --git a/test/form/exported-empty-vars/_expected/es6.js b/test/form/exported-empty-vars/_expected/es6.js
index 8151c68..3be564f 100644
--- a/test/form/exported-empty-vars/_expected/es6.js
+++ b/test/form/exported-empty-vars/_expected/es6.js
@@ -3,7 +3,6 @@ foo = 42;
 
 var bar;
 var baz;
-
 bar = 43;
 baz = 44;
 
diff --git a/test/form/self-contained-bundle/_expected/amd.js b/test/form/self-contained-bundle/_expected/amd.js
index 5638a53..ed04c7c 100644
--- a/test/form/self-contained-bundle/_expected/amd.js
+++ b/test/form/self-contained-bundle/_expected/amd.js
@@ -8,7 +8,6 @@ define(function () { 'use strict';
 		return 42;
 	}
 
-
 	// comment before 1
 
 	console.log( 1 );
diff --git a/test/form/self-contained-bundle/_expected/cjs.js b/test/form/self-contained-bundle/_expected/cjs.js
index 8b0b5bd..8a71fe7 100644
--- a/test/form/self-contained-bundle/_expected/cjs.js
+++ b/test/form/self-contained-bundle/_expected/cjs.js
@@ -8,7 +8,6 @@ function bar () {
 	return 42;
 }
 
-
 // comment before 1
 
 console.log( 1 );
diff --git a/test/form/self-contained-bundle/_expected/es6.js b/test/form/self-contained-bundle/_expected/es6.js
index def67b9..7d5460c 100644
--- a/test/form/self-contained-bundle/_expected/es6.js
+++ b/test/form/self-contained-bundle/_expected/es6.js
@@ -6,7 +6,6 @@ function bar () {
 	return 42;
 }
 
-
 // comment before 1
 
 console.log( 1 );
diff --git a/test/form/self-contained-bundle/_expected/iife.js b/test/form/self-contained-bundle/_expected/iife.js
index 1ec92be..46f6561 100644
--- a/test/form/self-contained-bundle/_expected/iife.js
+++ b/test/form/self-contained-bundle/_expected/iife.js
@@ -8,7 +8,6 @@
 		return 42;
 	}
 
-
 	// comment before 1
 
 	console.log( 1 );
diff --git a/test/form/self-contained-bundle/_expected/umd.js b/test/form/self-contained-bundle/_expected/umd.js
index 854c4e4..51b72b0 100644
--- a/test/form/self-contained-bundle/_expected/umd.js
+++ b/test/form/self-contained-bundle/_expected/umd.js
@@ -12,7 +12,6 @@
 		return 42;
 	}
 
-
 	// comment before 1
 
 	console.log( 1 );
diff --git a/test/function/unused-var-a/_config.js b/test/function/unused-var-a/_config.js
new file mode 100644
index 0000000..05a2b74
--- /dev/null
+++ b/test/function/unused-var-a/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'omits unused var declaration (a)'
+};
diff --git a/test/function/unused-var-a/foo.js b/test/function/unused-var-a/foo.js
new file mode 100644
index 0000000..ef10681
--- /dev/null
+++ b/test/function/unused-var-a/foo.js
@@ -0,0 +1,2 @@
+var unused = 'unused', foo = 'foo', bar = 'bar';
+export { foo, bar };
diff --git a/test/function/unused-var-a/main.js b/test/function/unused-var-a/main.js
new file mode 100644
index 0000000..9922892
--- /dev/null
+++ b/test/function/unused-var-a/main.js
@@ -0,0 +1,4 @@
+import { foo, bar } from './foo';
+
+assert.equal( foo, 'foo' );
+assert.equal( bar, 'bar' );
diff --git a/test/function/unused-var-b/_config.js b/test/function/unused-var-b/_config.js
new file mode 100644
index 0000000..174d9fe
--- /dev/null
+++ b/test/function/unused-var-b/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'omits unused var declaration (b)'
+};
diff --git a/test/function/unused-var-b/foo.js b/test/function/unused-var-b/foo.js
new file mode 100644
index 0000000..26a8538
--- /dev/null
+++ b/test/function/unused-var-b/foo.js
@@ -0,0 +1,2 @@
+var foo = 'foo', unused = 'unused', bar = 'bar';
+export { foo, bar };
diff --git a/test/function/unused-var-b/main.js b/test/function/unused-var-b/main.js
new file mode 100644
index 0000000..9922892
--- /dev/null
+++ b/test/function/unused-var-b/main.js
@@ -0,0 +1,4 @@
+import { foo, bar } from './foo';
+
+assert.equal( foo, 'foo' );
+assert.equal( bar, 'bar' );
diff --git a/test/function/unused-var-c/_config.js b/test/function/unused-var-c/_config.js
new file mode 100644
index 0000000..e40d968
--- /dev/null
+++ b/test/function/unused-var-c/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'omits unused var declaration (c)'
+};
diff --git a/test/function/unused-var-c/foo.js b/test/function/unused-var-c/foo.js
new file mode 100644
index 0000000..14e28bb
--- /dev/null
+++ b/test/function/unused-var-c/foo.js
@@ -0,0 +1,2 @@
+var foo = 'foo', bar = 'bar', unused = 'unused';
+export { foo, bar };
diff --git a/test/function/unused-var-c/main.js b/test/function/unused-var-c/main.js
new file mode 100644
index 0000000..9922892
--- /dev/null
+++ b/test/function/unused-var-c/main.js
@@ -0,0 +1,4 @@
+import { foo, bar } from './foo';
+
+assert.equal( foo, 'foo' );
+assert.equal( bar, 'bar' );
diff --git a/test/function/unused-var-d/_config.js b/test/function/unused-var-d/_config.js
new file mode 100644
index 0000000..78379d6
--- /dev/null
+++ b/test/function/unused-var-d/_config.js
@@ -0,0 +1,3 @@
+module.exports = {
+	description: 'omits unused var declaration (d)'
+};
diff --git a/test/function/unused-var-d/foo.js b/test/function/unused-var-d/foo.js
new file mode 100644
index 0000000..630ff46
--- /dev/null
+++ b/test/function/unused-var-d/foo.js
@@ -0,0 +1,5 @@
+var unused_a = 'a', unused_b = 'b';
+var unused_c = 'c';
+var foo = 'foo', bar = 'bar';
+
+export { foo, bar };
diff --git a/test/function/unused-var-d/main.js b/test/function/unused-var-d/main.js
new file mode 100644
index 0000000..9922892
--- /dev/null
+++ b/test/function/unused-var-d/main.js
@@ -0,0 +1,4 @@
+import { foo, bar } from './foo';
+
+assert.equal( foo, 'foo' );
+assert.equal( bar, 'bar' );