diff --git a/src/Module.js b/src/Module.js
index ce59dee..746a96d 100644
--- a/src/Module.js
+++ b/src/Module.js
@@ -324,7 +324,10 @@ export default class Module {
 		});
 
 		this.exportAllModules.forEach( module => {
-			if ( module.isExternal ) return; // TODO
+			if ( module.isExternal ) {
+				exports[ `*${module.id}` ] = true;
+				return;
+			}
 
 			module.getExports().forEach( name => {
 				if ( name !== 'default' ) exports[ name ] = true;
diff --git a/src/finalisers/amd.js b/src/finalisers/amd.js
index efe1a8e..55ca3e5 100644
--- a/src/finalisers/amd.js
+++ b/src/finalisers/amd.js
@@ -27,7 +27,7 @@ export default function amd ( bundle, magicString, { exportMode, indentString, i
 
 	if ( intro ) magicString.prepend( intro );
 
-	const exportBlock = getExportBlock( bundle.entryModule, exportMode );
+	const exportBlock = getExportBlock( bundle, exportMode );
 	if ( exportBlock ) magicString.append( '\n\n' + exportBlock );
 	if ( exportMode === 'named' && options.legacy !== true ) magicString.append( `\n\n${esModuleExport}` );
 	if ( outro ) magicString.append( outro );
diff --git a/src/finalisers/cjs.js b/src/finalisers/cjs.js
index 17036e9..cb571c2 100644
--- a/src/finalisers/cjs.js
+++ b/src/finalisers/cjs.js
@@ -48,7 +48,7 @@ export default function cjs ( bundle, magicString, { exportMode, intro, outro },
 
 	magicString.prepend( intro );
 
-	const exportBlock = getExportBlock( bundle.entryModule, exportMode, 'module.exports =' );
+	const exportBlock = getExportBlock( bundle, exportMode, 'module.exports =' );
 	if ( exportBlock ) magicString.append( '\n\n' + exportBlock );
 	if ( outro ) magicString.append( outro );
 
diff --git a/src/finalisers/es.js b/src/finalisers/es.js
index b2123bb..319d398 100644
--- a/src/finalisers/es.js
+++ b/src/finalisers/es.js
@@ -6,6 +6,10 @@ function notDefault ( name ) {
 
 export default function es ( bundle, magicString, { intro, outro } ) {
 	const importBlock = bundle.externalModules
+		.filter( module => {
+			const imported = keys( module.declarations );
+			return imported.length !== 1 || imported[0][0] !== '*';
+		})
 		.map( module => {
 			const specifiers = [];
 			const specifiersList = [specifiers];
@@ -13,11 +17,16 @@ export default function es ( bundle, magicString, { intro, outro } ) {
 				.filter( name => name !== '*' && name !== 'default' )
 				.filter( name => module.declarations[ name ].activated )
 				.map( name => {
+					if ( name[0] === '*' ) {
+						return `* as ${module.name}`;
+					}
+
 					const declaration = module.declarations[ name ];
 
 					if ( declaration.name === declaration.safeName ) return declaration.name;
 					return `${declaration.name} as ${declaration.safeName}`;
-				});
+				})
+				.filter( Boolean );
 
 			if ( module.declarations.default ) {
 				if ( module.exportsNamespace ) {
@@ -55,14 +64,25 @@ export default function es ( bundle, magicString, { intro, outro } ) {
 
 	const module = bundle.entryModule;
 
-	const specifiers = module.getExports().filter( notDefault ).map( name => {
-		const declaration = module.traceExport( name );
-		const rendered = declaration.getName( true );
+	const exportAllDeclarations = [];
+
+	const specifiers = module.getExports()
+		.filter( notDefault )
+		.map( name => {
+			const declaration = module.traceExport( name );
+			const rendered = declaration.getName( true );
 
-		return rendered === name ?
-			name :
-			`${rendered} as ${name}`;
-	});
+			if ( name[0] === '*' ) {
+				// export * from 'external'
+				exportAllDeclarations.push( `export * from '${name.slice( 1 )}';` );
+				return;
+			}
+
+			return rendered === name ?
+				name :
+				`${rendered} as ${name}`;
+		})
+		.filter( Boolean );
 
 	let exportBlock = specifiers.length ? `export { ${specifiers.join(', ')} };` : '';
 
@@ -72,6 +92,7 @@ export default function es ( bundle, magicString, { intro, outro } ) {
 	}
 
 	if ( exportBlock ) magicString.append( '\n\n' + exportBlock.trim() );
+	if ( exportAllDeclarations.length ) magicString.append( '\n\n' + exportAllDeclarations.join( '\n' ).trim() );
 	if ( outro ) magicString.append( outro );
 
 	return magicString.trim();
diff --git a/src/finalisers/iife.js b/src/finalisers/iife.js
index f2c6902..239cdb5 100644
--- a/src/finalisers/iife.js
+++ b/src/finalisers/iife.js
@@ -65,7 +65,7 @@ export default function iife ( bundle, magicString, { exportMode, indentString,
 
 	if ( intro ) magicString.prepend( intro );
 
-	const exportBlock = getExportBlock( bundle.entryModule, exportMode );
+	const exportBlock = getExportBlock( bundle, exportMode );
 	if ( exportBlock ) magicString.append( '\n\n' + exportBlock );
 	if ( outro ) magicString.append( outro );
 
diff --git a/src/finalisers/shared/getExportBlock.js b/src/finalisers/shared/getExportBlock.js
index 5a7f34f..0345dd6 100644
--- a/src/finalisers/shared/getExportBlock.js
+++ b/src/finalisers/shared/getExportBlock.js
@@ -1,10 +1,20 @@
-export default function getExportBlock ( entryModule, exportMode, mechanism = 'return' ) {
+export default function getExportBlock ( bundle, exportMode, mechanism = 'return' ) {
+	const entryModule = bundle.entryModule;
+
 	if ( exportMode === 'default' ) {
 		return `${mechanism} ${entryModule.traceExport( 'default' ).getName( false )};`;
 	}
 
 	return entryModule.getExports()
 		.map( name => {
+			if ( name[0] === '*' ) {
+				// export all from external
+				const id = name.slice( 1 );
+				const module = bundle.moduleById.get( id );
+
+				return `Object.keys(${module.name}).forEach(function (key) { exports[key] = ${module.name}[key]; });`;
+			}
+
 			const prop = name === 'default' ? `['default']` : `.${name}`;
 			const declaration = entryModule.traceExport( name );
 
diff --git a/src/finalisers/umd.js b/src/finalisers/umd.js
index 5102e2b..0a93e03 100644
--- a/src/finalisers/umd.js
+++ b/src/finalisers/umd.js
@@ -86,7 +86,7 @@ export default function umd ( bundle, magicString, { exportMode, indentString, i
 
 	if ( intro ) magicString.prepend( intro );
 
-	const exportBlock = getExportBlock( bundle.entryModule, exportMode );
+	const exportBlock = getExportBlock( bundle, exportMode );
 	if ( exportBlock ) magicString.append( '\n\n' + exportBlock );
 	if ( exportMode === 'named' && options.legacy !== true ) magicString.append( `\n\n${esModuleExport}` );
 	if ( outro ) magicString.append( outro );
diff --git a/test/form/reexports-from-external/_config.js b/test/form/reexports-from-external/_config.js
new file mode 100644
index 0000000..58c5eff
--- /dev/null
+++ b/test/form/reexports-from-external/_config.js
@@ -0,0 +1,9 @@
+const assert = require( 'assert' );
+
+module.exports = {
+	description: 're-exports * from external module (#791)',
+	options: {
+		external: [ 'external' ],
+		moduleName: 'myBundle'
+	}
+};
diff --git a/test/form/reexports-from-external/_expected/amd.js b/test/form/reexports-from-external/_expected/amd.js
new file mode 100644
index 0000000..ae628ce
--- /dev/null
+++ b/test/form/reexports-from-external/_expected/amd.js
@@ -0,0 +1,9 @@
+define(['exports', 'external'], function (exports, external) { 'use strict';
+
+
+
+	Object.keys(external).forEach(function (key) { exports[key] = external[key]; });
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+});
diff --git a/test/form/reexports-from-external/_expected/cjs.js b/test/form/reexports-from-external/_expected/cjs.js
new file mode 100644
index 0000000..8fe0297
--- /dev/null
+++ b/test/form/reexports-from-external/_expected/cjs.js
@@ -0,0 +1,9 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', { value: true });
+
+var external = require('external');
+
+
+
+Object.keys(external).forEach(function (key) { exports[key] = external[key]; });
diff --git a/test/form/reexports-from-external/_expected/es.js b/test/form/reexports-from-external/_expected/es.js
new file mode 100644
index 0000000..4953eb6
--- /dev/null
+++ b/test/form/reexports-from-external/_expected/es.js
@@ -0,0 +1 @@
+export * from 'external';
diff --git a/test/form/reexports-from-external/_expected/iife.js b/test/form/reexports-from-external/_expected/iife.js
new file mode 100644
index 0000000..6ce8e60
--- /dev/null
+++ b/test/form/reexports-from-external/_expected/iife.js
@@ -0,0 +1,8 @@
+(function (exports,external) {
+	'use strict';
+
+
+
+	Object.keys(external).forEach(function (key) { exports[key] = external[key]; });
+
+}((this.myBundle = this.myBundle || {}),external));
diff --git a/test/form/reexports-from-external/_expected/umd.js b/test/form/reexports-from-external/_expected/umd.js
new file mode 100644
index 0000000..554df0d
--- /dev/null
+++ b/test/form/reexports-from-external/_expected/umd.js
@@ -0,0 +1,11 @@
+(function (global, factory) {
+	typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('external')) :
+	typeof define === 'function' && define.amd ? define(['exports', 'external'], factory) :
+	(factory((global.myBundle = global.myBundle || {}),global.external));
+}(this, (function (exports,external) { 'use strict';
+
+	Object.keys(external).forEach(function (key) { exports[key] = external[key]; });
+
+	Object.defineProperty(exports, '__esModule', { value: true });
+
+})));
diff --git a/test/form/reexports-from-external/main.js b/test/form/reexports-from-external/main.js
new file mode 100644
index 0000000..4953eb6
--- /dev/null
+++ b/test/form/reexports-from-external/main.js
@@ -0,0 +1 @@
+export * from 'external';
diff --git a/test/function/reexports-from-external/_config.js b/test/function/reexports-from-external/_config.js
new file mode 100644
index 0000000..c61fdfc
--- /dev/null
+++ b/test/function/reexports-from-external/_config.js
@@ -0,0 +1,22 @@
+const assert = require( 'assert' );
+
+module.exports = {
+	description: 're-exports * from external module (#791)',
+	options: {
+		external: [ 'external' ]
+	},
+	context: {
+		require ( id ) {
+			if ( id === 'external' ) {
+				return {
+					foo: 1,
+					bar: 2
+				};
+			}
+		}
+	},
+	exports: exports => {
+		assert.equal( exports.foo, 1 );
+		assert.equal( exports.bar, 2 );
+	}
+};
diff --git a/test/function/reexports-from-external/main.js b/test/function/reexports-from-external/main.js
new file mode 100644
index 0000000..4953eb6
--- /dev/null
+++ b/test/function/reexports-from-external/main.js
@@ -0,0 +1 @@
+export * from 'external';