diff --git a/src/ECharts.ts b/src/ECharts.ts
index 89c100b..6027a53 100644
--- a/src/ECharts.ts
+++ b/src/ECharts.ts
@@ -12,7 +12,6 @@ import {
   onMounted,
   onUnmounted,
   h,
-  mergeProps,
   PropType,
   watchEffect,
   Vue2
@@ -36,7 +35,7 @@ import {
   loadingProps
 } from "./composables";
 import "./style.css";
-import { filterObjectValue } from "./utils";
+import { omitOn } from "./utils";
 
 const TAG_NAME = "x-vue-echarts";
 
@@ -95,9 +94,7 @@ export default defineComponent({
     const initOptions = toRef(props, "initOptions");
     const loadingOptions = toRef(props, "loadingOptions");
 
-    const nonEventAttrs = computed(() =>
-      filterObjectValue(attrs, value => typeof value !== "function")
-    );
+    const nonEventAttrs = computed(() => omitOn(attrs));
 
     function init(option?: Option) {
       if (chart.value || !root.value) {
@@ -244,9 +241,9 @@ export default defineComponent({
     return exposed;
   },
   render() {
-    return h(
-      TAG_NAME,
-      mergeProps({ class: "echarts", ref: "root" }, this.nonEventAttrs)
-    );
+    const attrs = { ...this.nonEventAttrs };
+    attrs.ref = "root";
+    attrs.class = attrs.class ? ["echarts"].concat(attrs.class) : "echarts";
+    return h(TAG_NAME, attrs);
   }
 });
diff --git a/src/utils.ts b/src/utils.ts
index c6d1db2..15d0620 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,16 +1,20 @@
 type Attrs = {
-  [key: string]: unknown;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  [key: string]: any;
 };
 
-export function filterObjectValue(
-  source: Attrs,
-  predicate: (key: unknown) => boolean
-) {
-  const target: Attrs = {};
-  for (const key in source) {
-    if (predicate(source[key])) {
-      target[key] = source[key];
+// Copied from
+// https://github.com/vuejs/vue-next/blob/5a7a1b8293822219283d6e267496bec02234b0bc/packages/shared/src/index.ts#L40-L41
+const onRE = /^on[^a-z]/;
+export const isOn = (key: string) => onRE.test(key);
+
+export function omitOn(attrs: Attrs) {
+  const result: Attrs = {};
+  for (const key in attrs) {
+    if (!isOn(key)) {
+      result[key] = attrs[key];
     }
   }
-  return target;
+
+  return result;
 }