diff --git a/src/core/importType.js b/src/core/importType.js
index 6e4ac9a4da..d40bf9fbc9 100644
--- a/src/core/importType.js
+++ b/src/core/importType.js
@@ -29,7 +29,7 @@ export function isExternalModule(name, settings, path, context) {
   if (arguments.length < 4) {
     throw new TypeError('isExternalModule: name, settings, path, and context are all required');
   }
-  return isModule(name) && isExternalPath(name, settings, path, getContextPackagePath(context));
+  return (isModule(name) || isScopedModule(name)) && isExternalPath(name, settings, path, getContextPackagePath(context));
 }
 
 export function isExternalModuleMain(name, settings, path, context) {
diff --git a/tests/src/core/importType.js b/tests/src/core/importType.js
index 0dcd5266bb..f0350ecb8f 100644
--- a/tests/src/core/importType.js
+++ b/tests/src/core/importType.js
@@ -234,11 +234,21 @@ describe('importType(name)', function () {
   it('`isExternalModule` works with windows directory separator', function () {
     const context = testContext();
     expect(isExternalModule('foo', {}, 'E:\\path\\to\\node_modules\\foo', context)).to.equal(true);
+    expect(isExternalModule('@foo/bar', {}, 'E:\\path\\to\\node_modules\\@foo\\bar', context)).to.equal(true);
     expect(isExternalModule('foo', {
       'import/external-module-folders': ['E:\\path\\to\\node_modules'],
     }, 'E:\\path\\to\\node_modules\\foo', context)).to.equal(true);
   });
 
+  it('`isExternalModule` works with unix directory separator', function () {
+    const context = testContext();
+    expect(isExternalModule('foo', {}, '/path/to/node_modules/foo', context)).to.equal(true);
+    expect(isExternalModule('@foo/bar', {}, '/path/to/node_modules/@foo/bar', context)).to.equal(true);
+    expect(isExternalModule('foo', {
+      'import/external-module-folders': ['/path/to/node_modules'],
+    }, '/path/to/node_modules/foo', context)).to.equal(true);
+  });
+
   it('correctly identifies scoped modules with `isScopedModule`', () => {
     expect(isScopedModule('@/abc')).to.equal(false);
     expect(isScopedModule('@/abc/def')).to.equal(false);