Use function(exports), not function('exports').
@ -16,7 +16,7 @@ export default function umd ( bundle, magicString, exportMode, options ) {
if ( exportMode === 'named' ) {
amdDeps.unshift( `'exports'` );
cjsDeps.unshift( `'exports'` );
cjsDeps.unshift( `exports` );
globalDeps.unshift( `(global.${options.moduleName} = {})` );
args.unshift( 'exports' );