diff --git a/doc/learning/overview.md b/doc/learning/overview.md
index a9448cb9..46605028 100644
--- a/doc/learning/overview.md
+++ b/doc/learning/overview.md
@@ -96,7 +96,7 @@ class OrderLine extends Component {
     </div>`;
 
   add() {
-    this.trigger("add-to-order", { line: props.line });
+    this.trigger("add-to-order", { line: this.props.line });
   }
 }