diff --git a/package.json b/package.json
index e1cb4e4..c1692f3 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@tp/tp-checkbox",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "description": "",
   "main": "tp-checkbox.js",
   "scripts": {
diff --git a/tp-checkbox.js b/tp-checkbox.js
index dc6c805..22b9ca2 100644
--- a/tp-checkbox.js
+++ b/tp-checkbox.js
@@ -72,6 +72,7 @@ class TpCheckbox extends Inert(ControlState(FormElement(LitElement))) {
     return {
       checked: { type: Boolean, reflect: true },
       role: { type: String, reflect: true },
+      invalid: { type: Boolean, reflect: true },
       _value: { type: String },
     };
   }
@@ -99,6 +100,16 @@ class TpCheckbox extends Inert(ControlState(FormElement(LitElement))) {
     }
   }
 
+  validate() {
+    if (this.required && !this.checked) {
+      this.invalid = true;
+      return false;
+    }
+
+    this.invalid = false;
+    return true;
+  }
+
   get value() {
     if (this._value !== '') {
       return this._value;