diff --git a/data/README.md b/data/README.md
index 07a854bf2c000..304eec312456f 100644
--- a/data/README.md
+++ b/data/README.md
@@ -55,7 +55,7 @@ registerStore( 'my-shop', {
 	},
 
 	selectors: {
-		getPrice( item ) {
+		getPrice( state, item ) {
 			const { prices, discountPercent } = state;
 			const price = prices[ item ];