diff --git a/docs/advanced/terraform.md b/docs/advanced/terraform.md
index 4b2118f8b8..e094e4ec02 100644
--- a/docs/advanced/terraform.md
+++ b/docs/advanced/terraform.md
@@ -28,7 +28,7 @@ resource "ko_build" "app" {
 
 // Report the build image's digest.
 output "image" {
-  value = ko_build.app.image
+  value = ko_build.app.image_ref
 }
 ```