diff --git a/frontend/src/scripts/index.js b/frontend/src/scripts/index.js
index c61bf91..8bf5293 100644
--- a/frontend/src/scripts/index.js
+++ b/frontend/src/scripts/index.js
@@ -45,7 +45,7 @@ class Main extends Component {
             this.setState({products: json})
         })
         fetch(addr_prefix + "/api/cart").then(resp => resp.json()).then(json => {
-            this.setState({cart: json})
+            this.setState({cart: [...json, ...this.state.cart]})
         })
         fetch(addr_prefix + "/api/login_status").then(resp => resp.json()).then(json => {
             this.setState({login_status: json})