diff --git a/serving/samples/source-to-url-go/README.md b/serving/samples/source-to-url-go/README.md
index 26719172e..4bf0f3bbd 100644
--- a/serving/samples/source-to-url-go/README.md
+++ b/serving/samples/source-to-url-go/README.md
@@ -117,7 +117,7 @@ spec:
             image: *image
             imagePullPolicy: Always
             env:
-            - name: TARGET
+            - name: SIMPLE_MSG
               value: "Hello sample app!"
 ```