diff --git a/package/package.json b/package/package.json
index a1ca6a311..99c126918 100644
--- a/package/package.json
+++ b/package/package.json
@@ -67,5 +67,8 @@
   "dependencies": {
     "dom7": "^3.0.0",
     "ssr-window": "^3.0.0"
+  },
+  "peerDependencies": {
+    "svelte": "^3.x"
   }
 }
\ No newline at end of file
diff --git a/scripts/build-js-core.js b/scripts/build-js-core.js
index 8c1146ba4..a3dcb9092 100644
--- a/scripts/build-js-core.js
+++ b/scripts/build-js-core.js
@@ -12,6 +12,7 @@ async function buildCore(components, format, cb) {
   const outputDir = env === 'development' ? 'build' : 'package';
   let coreContent = '';
   if (format === 'esm') {
+    coreContent += `export const __esModule = true;\n`;
     coreContent += `export { default as Swiper, default } from './components/core/core-class';\n`;
     coreContent += components
       .map(