diff --git a/src/Bundle.js b/src/Bundle.js
index fa64522..c62b138 100644
--- a/src/Bundle.js
+++ b/src/Bundle.js
@@ -87,12 +87,18 @@ export default class Bundle {
 			});
 	}
 
+	// TODO would be better to deconflict once, rather than per-render
 	deconflict ( es6 ) {
 		let definers = blank();
 		let conflicts = blank();
 
+		let allReplacements = blank();
+
 		// Assign names to external modules
 		this.externalModules.forEach( module => {
+			// while we're here...
+			allReplacements[ module.id ] = blank();
+
 			let name = makeLegalIdentifier( module.suggestedNames['*'] || module.suggestedNames.default || module.id );
 
 			while ( definers[ name ] ) {
@@ -107,6 +113,9 @@ export default class Bundle {
 
 		// Discover conflicts (i.e. two statements in separate modules both define `foo`)
 		this.orderedModules.forEach( module => {
+			// while we're here...
+			allReplacements[ module.id ] = blank();
+
 			module.statements.forEach( statement => {
 				if ( !statement.isIncluded ) return;
 
@@ -145,9 +154,61 @@ export default class Bundle {
 			modules.forEach( module => {
 				const replacement = getSafeName( name );
 				module.rename( name, replacement );
+				allReplacements[ module.id ][ name ] = replacement;
 			});
 		});
 
+		// Assign non-conflicting names to internal default/namespace export
+		this.orderedModules.forEach( module => {
+			if ( !module.needsDefault && !module.needsAll ) return;
+
+			if ( module.needsDefault ) {
+				const defaultExport = module.exports.default;
+
+				// only create a new name if either
+				//   a) it's an expression (`export default 42`) or
+				//   b) it's a name that is reassigned to (`export var a = 1; a = 2`)
+				if ( defaultExport.declaredName && !defaultExport.isModified ) return; // TODO encapsulate check for whether we need synthetic default name
+
+				const defaultName = getSafeName( module.suggestedNames.default );
+
+				module.replacements.default = defaultName;
+			}
+
+			// TODO namespace
+		});
+
+		this.orderedModules.forEach( module => {
+			keys( module.imports ).forEach( localName => {
+				if ( !module.imports[ localName ].isUsed ) return;
+
+				const bundleName = trace( module, localName );
+				if ( bundleName !== localName ) {
+					allReplacements[ module.id ][ localName ] = bundleName;
+				}
+			});
+		});
+
+		function trace ( module, localName ) {
+			const importDeclaration = module.imports[ localName ];
+
+			// defined in this module
+			if ( !importDeclaration ) {
+				return module.replacements[ localName ] || localName;
+			}
+
+			// defined elsewhere
+			const otherModule = importDeclaration.module;
+
+			if ( otherModule.isExternal ) {
+				// TODO ES6
+				return `${otherModule.name}.${importDeclaration.name}`;
+			}
+
+			const exportDeclaration = otherModule.exports[ importDeclaration.name ];
+			return trace( otherModule, exportDeclaration.localName );
+		}
+
 		// TODO assign names to default/namespace exports, based on suggestions
 		// TODO trace bindings and rename within modules here (rather than later
 		// with getCanonicalName)
@@ -160,6 +221,8 @@ export default class Bundle {
 			conflicts[ name ] = true;
 			return name;
 		}
+
+		return allReplacements;
 	}
 
 	fetchModule ( importee, importer ) {
@@ -262,7 +325,7 @@ export default class Bundle {
 
 	render ( options = {} ) {
 		const format = options.format || 'es6';
-		this.deconflict( format === 'es6' );
+		const allReplacements = this.deconflict( format === 'es6' );
 
 		// If we have named exports from the bundle, and those exports
 		// are assigned to *within* the bundle, we may need to rewrite e.g.
@@ -288,7 +351,7 @@ export default class Bundle {
 				const originalDeclaration = this.entryModule.findDeclaration( exportDeclaration.localName );
 
 				if ( originalDeclaration && originalDeclaration.type === 'VariableDeclaration' ) {
-					const canonicalName = this.entryModule.getCanonicalName( exportDeclaration.localName, false );
+					const canonicalName = this.entryModule.replacements[ exportDeclaration.localName ] || exportDeclaration.localName;
 
 					allBundleExports[ canonicalName ] = `exports.${key}`;
 					this.varExports[ key ] = true;
@@ -305,7 +368,7 @@ export default class Bundle {
 		let magicString = new MagicString.Bundle({ separator: '\n\n' });
 
 		this.orderedModules.forEach( module => {
-			const source = module.render( allBundleExports, format );
+			const source = module.render( allBundleExports, allReplacements[ module.id ], format );
 			if ( source.toString().length ) {
 				magicString.addSource( source );
 			}
@@ -316,10 +379,10 @@ export default class Bundle {
 		const namespaceBlock = this.internalNamespaceModules.map( module => {
 			const exportKeys = keys( module.exports );
 
-			return `var ${module.getCanonicalName('*', format === 'es6')} = {\n` +
+			return `var ${module.namespaceName} = {\n` +
 				exportKeys.map( key => {
 					const localName = module.exports[ key ].localName;
-					return `${indentString}get ${key} () { return ${module.getCanonicalName(localName, format === 'es6')}; }`;
+					return `${indentString}get ${key} () { return ${localName}; }`; // TODO...
 				}).join( ',\n' ) +
 			`\n};\n\n`;
 		}).join( '' );
diff --git a/src/ExternalModule.js b/src/ExternalModule.js
index 1406832..e24d42c 100644
--- a/src/ExternalModule.js
+++ b/src/ExternalModule.js
@@ -26,18 +26,6 @@ export default class ExternalModule {
 		return null;
 	}
 
-	getCanonicalName ( name, es6 ) {
-		if ( name === 'default' ) {
-			return this.needsNamed && !es6 ? `${this.name}__default` : this.name;
-		}
-
-		if ( name === '*' ) {
-			return this.name; // TODO is this correct in ES6?
-		}
-
-		return es6 ? ( this.canonicalNames[ name ] || name ) : `${this.name}.${name}`;
-	}
-
 	rename ( name, replacement ) {
 		this.canonicalNames[ name ] = replacement;
 	}
diff --git a/src/Module.js b/src/Module.js
index 92308d0..d231e56 100644
--- a/src/Module.js
+++ b/src/Module.js
@@ -19,11 +19,11 @@ function deconflict ( name, names ) {
 	return name;
 }
 
-function isEmptyExportedVarDeclaration ( node, module, allBundleExports, es6 ) {
+function isEmptyExportedVarDeclaration ( node, module, allBundleExports, moduleReplacements, es6 ) {
 	if ( node.type !== 'VariableDeclaration' || node.declarations[0].init ) return false;
 
 	const name = node.declarations[0].id.name;
-	const canonicalName = module.getCanonicalName( name, es6 );
+	const canonicalName = moduleReplacements[ name ];
 
 	return canonicalName in allBundleExports;
 }
@@ -62,7 +62,8 @@ export default class Module {
 		// array of all-export sources
 		this.exportDelegates = [];
 
-		this.canonicalNames = blank();
+		this.canonicalNames = blank(); // TODO still necessary?
+		this.replacements = blank();
 
 		this.definitions = blank();
 		this.definitionPromises = blank();
@@ -293,58 +294,6 @@ export default class Module {
 		return null;
 	}
 
-	getCanonicalName ( localName, es6 ) {
-		// Special case
-		if ( localName === 'default' && ( this.exports.default.isModified || !this.suggestedNames.default ) ) {
-			let canonicalName = makeLegalIdentifier( this.id.replace( dirname( this.bundle.entryModule.id ) + '/', '' ).replace( /\.js$/, '' ) );
-			return deconflict( canonicalName, this.definitions );
-		}
-
-		if ( this.suggestedNames[ localName ] ) {
-			localName = this.suggestedNames[ localName ];
-		}
-
-		const id = localName + ( es6 ? '-es6' : '' ); // TODO ugh this seems like a terrible hack
-
-		if ( !this.canonicalNames[ id ] ) {
-			let canonicalName;
-
-			if ( this.imports[ localName ] ) {
-				const importDeclaration = this.imports[ localName ];
-				const module = importDeclaration.module;
-
-				if ( importDeclaration.name === '*' ) {
-					canonicalName = module.suggestedNames[ '*' ];
-				} else {
-					let exporterLocalName;
-
-					if ( module.isExternal ) {
-						exporterLocalName = importDeclaration.name;
-					} else {
-						const exportDeclaration = module.exports[ importDeclaration.name ];
-
-						// The export declaration of the particular name is known.
-						if (exportDeclaration) {
-							exporterLocalName = exportDeclaration.localName;
-						} else { // export * from '...'
-							exporterLocalName = importDeclaration.name;
-						}
-					}
-
-					canonicalName = module.getCanonicalName( exporterLocalName, es6 );
-				}
-			}
-
-			else {
-				canonicalName = localName;
-			}
-
-			this.canonicalNames[ id ] = canonicalName;
-		}
-
-		return this.canonicalNames[ id ];
-	}
-
 	mark ( name ) {
 		// shortcut cycles. TODO this won't work everywhere...
 		if ( this.definitionPromises[ name ] ) {
@@ -356,6 +305,7 @@ export default class Module {
 		// The definition for this name is in a different module
 		if ( this.imports[ name ] ) {
 			const importDeclaration = this.imports[ name ];
+			importDeclaration.isUsed = true;
 
 			promise = this.bundle.fetchModule( importDeclaration.source, this.id )
 				.then( module => {
@@ -380,15 +330,15 @@ export default class Module {
 						module.suggestName( 'default', `${suggestion}__default` );
 					}
 
-					if ( module.isExternal ) {
-						if ( importDeclaration.name === 'default' ) {
-							module.needsDefault = true;
-						} else if ( importDeclaration.name === '*' ) {
-							module.needsAll = true;
-						} else {
-							module.needsNamed = true;
-						}
+					if ( importDeclaration.name === 'default' ) {
+						module.needsDefault = true;
+					} else if ( importDeclaration.name === '*' ) {
+						module.needsAll = true;
+					} else {
+						module.needsNamed = true;
+					}
 
+					if ( module.isExternal ) {
 						module.importedByBundle.push( importDeclaration );
 						return emptyArrayPromise;
 					}
@@ -601,11 +551,10 @@ export default class Module {
 	}
 
 	rename ( name, replacement ) {
-		// TODO again, hacky...
-		this.canonicalNames[ name ] = this.canonicalNames[ name + '-es6' ] = replacement;
+		this.replacements[ name ] = replacement;
 	}
 
-	render ( allBundleExports, format ) {
+	render ( allBundleExports, moduleReplacements, format ) {
 		let magicString = this.magicString.clone();
 
 		this.statements.forEach( statement => {
@@ -623,7 +572,7 @@ export default class Module {
 				}
 
 				// skip `export var foo;` if foo is exported
-				if ( isEmptyExportedVarDeclaration( statement.node.declaration, this, allBundleExports, format === 'es6' ) ) {
+				if ( isEmptyExportedVarDeclaration( statement.node.declaration, this, allBundleExports, moduleReplacements, format === 'es6' ) ) {
 					magicString.remove( statement.start, statement.next );
 					return;
 				}
@@ -631,7 +580,7 @@ export default class Module {
 
 			// skip empty var declarations for exported bindings
 			// (otherwise we're left with `exports.foo;`, which is useless)
-			if ( isEmptyExportedVarDeclaration( statement.node, this, allBundleExports, format === 'es6' ) ) {
+			if ( isEmptyExportedVarDeclaration( statement.node, this, allBundleExports, moduleReplacements, format === 'es6' ) ) {
 				magicString.remove( statement.start, statement.next );
 				return;
 			}
@@ -652,12 +601,12 @@ export default class Module {
 			keys( statement.dependsOn )
 				.concat( keys( statement.defines ) )
 				.forEach( name => {
-					const canonicalName = this.getCanonicalName( name, format === 'es6' );
+					const bundleName = moduleReplacements[ name ] || name;
 
-					if ( allBundleExports[ canonicalName ] ) {
-						bundleExports[ name ] = replacements[ name ] = allBundleExports[ canonicalName ];
-					} else if ( name !== canonicalName ) {
-						replacements[ name ] = canonicalName;
+					if ( allBundleExports[ bundleName ] ) {
+						bundleExports[ name ] = replacements[ name ] = allBundleExports[ bundleName ];
+					} else if ( bundleName !== name ) { // TODO weird structure
+						replacements[ name ] = bundleName;
 					}
 				});
 
@@ -677,9 +626,16 @@ export default class Module {
 				}
 
 				else if ( statement.node.type === 'ExportDefaultDeclaration' ) {
-					const canonicalName = this.getCanonicalName( 'default', format === 'es6' );
+					//const canonicalName = this.getCanonicalName( 'default', format === 'es6' );
+					let canonicalName;
+					if ( this.replacements.default ) {
+						canonicalName = this.replacements.default;
+					} else {
+						canonicalName = statement.node.declaration.name; // TODO declaredName?
+						canonicalName = this.replacements[ canonicalName ] || canonicalName;
+					}
 
-					if ( statement.node.declaration.type === 'Identifier' && canonicalName === this.getCanonicalName( statement.node.declaration.name, format === 'es6' ) ) {
+					if ( statement.node.declaration.type === 'Identifier' && canonicalName === ( moduleReplacements[ statement.node.declaration.name ] || statement.node.declaration.name ) ) {
 						magicString.remove( statement.start, statement.next );
 						return;
 					}
diff --git a/src/finalisers/es6.js b/src/finalisers/es6.js
index 85c25ce..8daa5cf 100644
--- a/src/finalisers/es6.js
+++ b/src/finalisers/es6.js
@@ -37,7 +37,7 @@ export default function es6 ( bundle, magicString ) {
 	const exportBlock = keys( exports ).map( exportedName => {
 		const specifier = exports[ exportedName ];
 
-		const canonicalName = bundle.entryModule.getCanonicalName( specifier.localName );
+		const canonicalName = bundle.entryModule.replacements[ specifier.localName ] || specifier.localName;
 
 		if ( exportedName === 'default' ) {
 			return `export default ${canonicalName};`;
diff --git a/src/finalisers/shared/getExportBlock.js b/src/finalisers/shared/getExportBlock.js
index c02c727..ca91179 100644
--- a/src/finalisers/shared/getExportBlock.js
+++ b/src/finalisers/shared/getExportBlock.js
@@ -1,12 +1,13 @@
 export default function getExportBlock ( bundle, exportMode, mechanism = 'return' ) {
 	if ( exportMode === 'default' ) {
-		return `${mechanism} ${bundle.entryModule.getCanonicalName('default')};`;
+		return `${mechanism} ${bundle.entryModule.replacements.default};`;
 	}
 
 	return bundle.toExport
 		.map( name => {
 			const prop = name === 'default' ? `['default']` : `.${name}`;
-			return `exports${prop} = ${bundle.entryModule.getCanonicalName(name)};`;
+			name = bundle.entryModule.replacements[ name ] || name;
+			return `exports${prop} = ${name};`;
 		})
 		.join( '\n' );
 }